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DIY Stompboxes => Building your own stompbox => Topic started by: dano12 on December 11, 2007, 07:51:24 PM

Title: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 11, 2007, 07:51:24 PM
Matsumin's Valve Caster, a 12AU7-based booster and light overdrive running at 9 volts. A very fun little circuit that has a minimal parts count and actually generates a good amount of boost and some overdrive.

It appears Matsumin's site has gone 404'd on us, but here is my redrawn schematic with a few cap substitutions.

(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCaster.gif)

You can even run this one of a 9 volt battery if you don't mind chewing through batteries :) Otherwise, and 9 volt adaptor will be fine.

I was particularly surprised as to the effectiveness of the simple tone control...

Enjoy!

<edit: also simple enough to build 90% of the circuit right on the back of a tube socket>
(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCaster_OnSocket.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Marcos - Munky on December 11, 2007, 09:16:12 PM
Cool!!! Any soundclips? I have only one tube, and don't know what to built with it, so I ask for soundclips to know how it sounds.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 11, 2007, 09:31:18 PM
Nice

Anymore pics of the whole circut?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on December 11, 2007, 11:04:42 PM
Not that familiar with tubes....

but 12au7....can this be a 12ax7 in this case?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on December 11, 2007, 11:19:42 PM
After a little more research, it seems that au and ax are correct pin for pin, and the ax has about 7x more gain than au. However, i dont know if it is possible to run the ax in this circuit due to 9vdc?

Also how will the sound be? If its more overdriven, that could be a good thing. I'm just looking to get into tubes a little
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MasaRGR on December 11, 2007, 11:37:09 PM
It appears Matsumin's site has gone 404'd on us, but here is my redrawn schematic with a few cap substitutions.

He moved his site recently to a new address http://www.matsumin.net/ (http://www.matsumin.net/)

Thanks for the schematic! Looks like fun :)


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 12, 2007, 12:43:28 AM
this is getting built this weekend!  got all the bits sitting around.  Nice bit of tube mojo to add to the pedal board I think  :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: jakenold on December 12, 2007, 03:02:07 AM
Nice work dano!

I was wondering, what needs to be changed say I want to run this at high voltage?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 12, 2007, 09:22:41 AM
Quote
Cool!!! Any soundclips? I have only one tube, and don't know what to built with it, so I ask for soundclips to know how it sounds.
No clips yet, but it sounds pretty nice. On the overdrive side it is a bit raspy, but I think that could be tamed with some filtering caps.

Quote
Anymore pics of the whole circut?
Will try and box it up tonight for pix!

Quote
but 12au7....can this be a 12ax7 in this case?
If I remember correctly, the relative gain of the 12A*7 tubes goes something like this:
12AU7   20
12AV7   40
12AY7   50
12AT7   60
12AX7   100

I built it wih the 12AU7/12U7 as specified on the schematic. I tried a 12AT7 and it was too much gain and sounded really bad. I also tried a couple of 12AX7s and it sounded even worse--pretty much unusable. I'm not really very knowledgeable about biasing tubes, but I suspect using an AT7 or AX7 will require resistor value changes.

Quote
After a little more research, it seems that au and ax are correct pin for pin, and the ax has about 7x more gain than au. However, i dont know if it is possible to run the ax in this circuit due to 9vdc?

From the little I know, you'll probably want to go up to 12vDC to use the AX7. Here's a diagram for using a 12AX7 as a clipper pair based on info from another thread here:
(http://www.beavisaudio.com/Projects/ValveCaster/TubesAsClippers.gif)

So 12 volt to heater 4 and heater 5 to ground might work.

Quote
He moved his site recently to a new address http://www.matsumin.net/
Thanks very much for the link! I'll update my schemo tonight to add the new URL.

Quote
Nice work dano! I was wondering, what needs to be changed say I want to run this at high voltage?

I think this design made the usual compromises to run at low voltage. If you are going to create a tube boost/overdrive and are using high voltage, that are lots of better designs out there.

Thanks to Matsumin for this fun circuit.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 12, 2007, 05:56:33 PM
Could you post a vero layout?

Does the tube light up btw?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 12, 2007, 08:03:21 PM
Could you post a vero layout?

Does the tube light up btw?

The tube will have to light up or it wouldn't conduct....

You could do as the picture above and put most components on the tube socket, or even a nice little tag board layout.  Its really such a simple build it might be a good learning excersize to try and make your own layout and then post it here and ask someone to check it over.  Should only take a short time  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on December 12, 2007, 08:08:43 PM
I may try this out. Does anyone have a spare 12au7 or socket?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 12, 2007, 08:53:35 PM
Vero is left as the dreaded "exercise for the reader". Mainly because I suck at vero. But you can build it entirely on the tube socket, pots and jacks.

And yes, it does glow!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 12, 2007, 09:02:53 PM
Could you post a vero layout?

Does the tube light up btw?

The tube will have to light up or it wouldn't conduct....

You could do as the picture above and put most components on the tube socket, or even a nice little tag board layout.  Its really such a simple build it might be a good learning excersize to try and make your own layout and then post it here and ask someone to check it over.  Should only take a short time  ;)

Alright thanks, that is probbly what I will do.

I am new to building frm schems.....Is this negative ground?

How do I wire the 3PDT? WHere is the input and output?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: the_random_hero on December 12, 2007, 09:07:04 PM
Vero is left as the dreaded "exercise for the reader". Mainly because I suck at vero. But you can build it entirely on the tube socket, pots and jacks.

And yes, it does glow!

Looks awesome, but have you tried running it on 12VDC? I'm sure you would get a lot nicer response out of it :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on December 12, 2007, 09:20:50 PM
I was just wondering the same thing...
Also, it seems like it could be a fantastic input stage in front of a 386 based practice amp or a speaker simulator. I'll try to get my hands on a 12AU7 and build one of those. Does it require an 8 pin socket? (sorry, completely clueless about tubes...)
Can anyone recommend a good supplier that will ship to Canada?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 12, 2007, 10:45:39 PM
^tubesandmore.com

If I remember correctly, the relative gain of the 12A*7 tubes goes something like this:
12AU7   20
12AV7   40
12AY7   50
12AT7   60
12AX7   100

If I wanted to use something besides a 12AU7 would I need to do any mods?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 13, 2007, 09:31:09 AM
Regarding the 386 amp, that's the route I'm taking with my wired tube socket thing. Trying to fit it in a small plastic case.

For the questions about using a tube other than the 12AU7, as said earlier, they are higher gain and won't work nicely unless you modify the circuit, I don't know how to do that part.

tubesandmore.com has the tube and sockets, it is the standard 9-pin tube socket you would use for guitar amp preamp sections.

Here is a rough *unverified* wiring diagram for anyone who wants to try it.

(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCasterWiring.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: GibsonGM on December 13, 2007, 09:47:24 AM
There are a few other circuits like this...the MarshaValve is one which feeds a JFET, I believe.  They're good ones to get started with tube work :o)
I think if you tried to modify the circuit for 12AX7 use, you might end up in a no-win situation....they're really supposed to run on 100+volts, and at 9v, that's just asking a lot!  But it's worth a try if you have something sitting on the breadboard.   There are also low-voltage tubes that would work nicely for a higher-gain setting.
Expect to blow thru batteries (use wall wart), the heaters draw a LOT of current!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: letsgocoyote on December 13, 2007, 02:35:02 PM
after building 32154 different electra and bazz fuss variations, i think this may end up being the first new kind of project to tackle!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 13, 2007, 02:57:21 PM
Dano thats a real clean layout you drew, what software you using and how long did you ahve to put into that?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 13, 2007, 05:04:30 PM
Regarding the 386 amp, that's the route I'm taking with my wired tube socket thing. Trying to fit it in a small plastic case.

For the questions about using a tube other than the 12AU7, as said earlier, they are higher gain and won't work nicely unless you modify the circuit, I don't know how to do that part.

tubesandmore.com has the tube and sockets, it is the standard 9-pin tube socket you would use for guitar amp preamp sections.

Here is a rough *unverified* wiring diagram for anyone who wants to try it.

(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCasterWiring.gif)

Thanks for the layout. It does however make it look like R2 is connected to pin 5 which is not the case.

Also why is lug 3 on the volume pot jumpered to lug 3 of the tone?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fuzz on December 13, 2007, 05:21:22 PM
Thanks for the layout. It does however make it look like R2 is connected to pin 5 which is not the case.

Also why is lug 3 on the volume pot jumpered to lug 3 of the tone?

R2 IS connected to pin 5, since both (R2 and pin 5) are connected to V+. Lug 3 of tone pot in jumpered to lug3 of volume pot just because the author inverted the order of tone pot & cap, with no remarkable differences.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 13, 2007, 06:02:38 PM
Dano thats a real clean layout you drew, what software you using and how long did you ahve to put into that?

Thanks dude. I use Microsoft Visio. That one took about 20 minutes.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 13, 2007, 06:05:09 PM

Thanks for the layout. It does however make it look like R2 is connected to pin 5 which is not the case.

Also why is lug 3 on the volume pot jumpered to lug 3 of the tone?

Some of the wires follow a rather tortuous route, but I'm pretty sure it is all correct at this point.

I've tried to share lugs as much as possible to reduce the number of wires needed.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 13, 2007, 06:13:59 PM
Cool

I also just realized there is no bypass switch. So basically I need to know which wire is the effect INPUT and OUTPUT. Thanks...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 13, 2007, 06:17:59 PM
I am not familiar with Visio at all  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on December 13, 2007, 06:39:15 PM
I think if you tried to modify the circuit for 12AX7 use, you might end up in a no-win situation....they're really supposed to run on 100+volts, and at 9v, that's just asking a lot!

Yeah... I think what you're going to run into is that the 12AX7's gain is high enough (in this topology) that, with only 9v to work with, it's automatically going to clip the bejeezus out of any but the tiniest of input signals.  You could redo the topology to cut gain and use some negative feedback, but then you'd get a squeaky clean sound, which probably isn't anything anyone would want.

I wouldn't doubt that the low gain was exactly why the 12AU7 was chosen.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 13, 2007, 07:55:30 PM
How does they look for a full layout?

(http://img292.imageshack.us/img292/1110/tubepedalpm0.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 14, 2007, 12:04:45 PM
No one?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on December 14, 2007, 12:40:24 PM
I think if you tried to modify the circuit for 12AX7 use, you might end up in a no-win situation....they're really supposed to run on 100+volts, and at 9v, that's just asking a lot!

Yeah... I think what you're going to run into is that the 12AX7's gain is high enough (in this topology) that, with only 9v to work with, it's automatically going to clip the bejeezus out of any but the tiniest of input signals.  You could redo the topology to cut gain and use some negative feedback, but then you'd get a squeaky clean sound, which probably isn't anything anyone would want.

I wouldn't doubt that the low gain was exactly why the 12AU7 was chosen.

Apologize for the newbish question. I am looking to try a tube project down the road and don't want to have to have a separate power supply on my board from my current. I get either 9 or 18 volts. Can this be converted to run of 18 instead of the 12 suggested for a 12AX7? Thanks

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 14, 2007, 01:50:07 PM
It's not good to run tube heaters that high, you can go lower than recommended 6.3V per heater (like this one does, with 4.5V per heater) but anything higher than 7V will reduce tube life noticeably. What you can do is put a resistor in series with heaters and run it of 18V, you'll get higher plate voltage which is good and you'll be able to tune heater voltage to 12.6V.
Let's see, if you start with 18V, minus 12.6V = 5.4V. From ohm's law you'll need resistance of approx. 5.6V/0.15mA = 37ohm. Approx power dissipation is 0.8W. I'd take 2W resistor of closest value to 37ohm. Any clearer?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on December 14, 2007, 02:08:57 PM
Quote
From ohm's law you'll need resistance of approx. 5.6V/0.15mA = 37ohm

Small typo!!! It is not 0.15mA, but either 0.15A or 150mA (which is the 12AX7/12AU7 heater current). All the others values are right!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on December 14, 2007, 04:37:48 PM
It's not good to run tube heaters that high, you can go lower than recommended 6.3V per heater (like this one does, with 4.5V per heater) but anything higher than 7V will reduce tube life noticeably. What you can do is put a resistor in series with heaters and run it of 18V, you'll get higher plate voltage which is good and you'll be able to tune heater voltage to 12.6V.
Let's see, if you start with 18V, minus 12.6V = 5.4V. From ohm's law you'll need resistance of approx. 5.6V/0.15mA = 37ohm. Approx power dissipation is 0.8W. I'd take 2W resistor of closest value to 37ohm. Any clearer?

So if I am reading this correctly, I can use the layout above, but add the proper resistor to lower the voltage down to approx 12.6volts and that should work? I have a couple 12Ax7's lying around which is why I am very interested in giving this a shot.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 14, 2007, 04:53:14 PM
good point, it's A, not mA :)

As you can read above, 12AX7 are not good candidates for this. Your voltage thingy is ok, however.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on December 14, 2007, 05:25:09 PM
I thought the problem with the 12AX7 was 9 volts was too low. If it was 12, that was okay. Did I mis-read. Again, new to building anything with a tube in it. If not, I will have to shop for a tube as well.

does the change from mA to A change the resistor value?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 14, 2007, 05:44:56 PM
yeah, changes 1000 times :)
with 0.15mA you'd need 37K resistor instead of 36 ohms.
If you want to utilize 12ax7 try something like shaka tube or tube driver.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on December 14, 2007, 10:16:48 PM
How does they look for a full layout?

(http://img292.imageshack.us/img292/1110/tubepedalpm0.jpg)
Anyone?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: LMJS on December 14, 2007, 10:49:44 PM
I think some of you guys will like this link http://www.takamine.co.uk/preamps/cooltube.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on December 14, 2007, 11:01:06 PM
I thought the problem with the 12AX7 was 9 volts was too low. If it was 12, that was okay. Did I mis-read. Again, new to building anything with a tube in it. If not, I will have to shop for a tube as well.

It wasn't really a tube-specific problem, it's that the gain of a 12AX7 is about 5 times as high as that of a 12AU7.  In the circuit shown, that would mean around 25 times more gain total.  So you might get a good clean out of it if you breathed gently on the strings, but anything more than that would clip.  I guess you could stick a pot in front of it, although that would raise the noise level.  Or always keep your guitar's volume control between 0.00 and 0.01.  But I suspect that you'd be happier in the long run if you spent the $8 and got a 12AU7.  That's not a very steep a price by tube equipment standards. ;-)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on December 15, 2007, 11:17:11 AM
Ahh. okay. slowly learning. the direction I was looking at took it from clean boost to tube distortion. sorry for taking the thread off in a different direction. Always in the process of learning. thanks for explanations on all of this.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on December 15, 2007, 08:41:47 PM
Hmmmm

Just got an 12ax7 in today for a tube driver or maybe an amp, and decided to try this out just because i couldn't look at the tube any longer without doing SOMETHING with it. I was expecting horrible sounds to come out of this. Unfortunately, no sounds :(   I get absolutely no noise, and the tube doesn't light up at all, and I know I have heard people talk of the tubes lighting up. Any thoughts? Are there any things that I may have done wrong as a first timer with tubes? (Such as the first time on an opamp when you dont connect 8 to v+ because it is ohmitted( ;D) from the schematic)

Thanks!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on December 16, 2007, 02:02:51 PM
This thread was talking about lighting a 12AX7 tube...
http://www.diystompboxes.com/smfforum/index.php?topic=63582.msg501595#msg501595

According to the thread you need to power the heaters it up to 12V.

-tR
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on December 16, 2007, 02:21:09 PM
THANKS!!

i build this in a few minutes today and sound great... 8)    more than expected for runnig at only 9 volts. :o

(http://img240.imageshack.us/img240/2711/valve9vdn9.th.jpg) (http://img240.imageshack.us/my.php?image=valve9vdn9.jpg)





Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on December 16, 2007, 02:58:00 PM
Nice job!
Any sound clips?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on December 16, 2007, 03:13:20 PM
i record this from my cell phone
http://www.youtube.com/watch?v=cdcORgmfPl4

the noise is my old amp not the pedal



ATENTION
The Tone Control works in wrong way,  change the wiring on the layout.!!!

 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SidSeizure on December 18, 2007, 11:37:34 AM
I've lurked here on and off for about a year and a half and I guess it's about time I asked a (possibly) stupid question.

Dano's (and Matsumin's) schematic reminds me a little of a Fuzz Face. So what I'd like to know is, would it be possible to make a sort of Fuzz Face using this tube instead of a pair of transistors? I searched the archives a little and found a couple of brief mentions of people wanting to use a tube (or two) in a Fuzz Face, but there weren't any details. (And sorry if this is a derail in Dano's thread.)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 18, 2007, 11:41:55 AM
I've lurked here on and off for about a year and a half and I guess it's about time I asked a (possibly) stupid question.

Dano's (and Matsumin's) schematic reminds me a little of a Fuzz Face. So what I'd like to know is, would it be possible to make a sort of Fuzz Face using this tube instead of a pair of transistors? I searched the archives a little and found a couple of brief mentions of people wanting to use a tube (or two) in a Fuzz Face, but there weren't any details. (And sorry if this is a derail in Dano's thread.)

There are possibly a couple of things you could do to make this distort more, along the lines of a fuzz. The first would be to add a pair of diode clippers at the end, before the tone control. Don't know if that would work with a tube, but it would be easy to try.

Another possible thing is to make two of them. Duplicate each tube stage where one feeds into another, that's four gain stages.

I wish there were 36 hours in a day, so many things to tinker with, so little time :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 18, 2007, 04:13:13 PM
if you want more distortion then really its time to leave this circuit behind....Its not really meant for that its just a boost.  Try the matchless hotbox thats a great build and not too hard I made one Banika who has made the layout software for us has a build report on his site.  Worth a look
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: suprleed on December 18, 2007, 05:28:03 PM
So many projects, so little time...

This looks very interesting.  I always wondered if there was a tube design that would run on only 9v.  Looks like this might be my first foray into the world of tubes (after I complete  3 other projects)!!!  :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 26, 2007, 12:40:07 AM
  Finally had time to try this circuit out today. Decent sound, not to bad. After checking out some tube data, the mini 6111 looked like a good candidate. Its a medium mu twin triode tube. Different pinout, so after changing a few things on the breadboard, popped the tube in the socket and fired it up.
  Wow, this sounds really good without having to tweak anything. As Dano stated, it chews through batteries quickly. I then hooked it up to an adjustable power supply to try higher and lower voltages. Using a 6111 tube run at 7 VDC, I would go as far as to say, this thing sounds great! A fat tone, decent sustain, and a nice, gritty, break up when the gain is cranked. A super simple, great sounding, one tube project.
  Thanks for posting this Dano.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on December 26, 2007, 02:42:44 AM
Any samples?
Thanks for the info. I  was going to order some tubes and wondered which ones would be best.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on December 26, 2007, 09:20:09 AM
  Finally had time to try this circuit out today. Decent sound, not to bad. After checking out some tube data, the mini 6111 looked like a good candidate. Its a medium mu twin triode tube. Different pinout, so after changing a few things on the breadboard, popped the tube in the socket and fired it up.
  Wow, this sounds really good without having to tweak anything. As Dano stated, it chews through batteries quickly. I then hooked it up to an adjustable power supply to try higher and lower voltages. Using a 6111 tube run at 7 VDC, I would go as far as to say, this thing sounds great! A fat tone, decent sustain, and a nice, gritty, break up when the gain is cranked. A super simple, great sounding, one tube project.
  Thanks for posting this Dano.
  Jered

For the 6111, did you have have to change anything other than the pinout? I'd like to try this....
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 26, 2007, 05:24:47 PM
  No, I didn't change anything except the pinout and voltage. I thought it sounded best at 7 volts, but the difference between 7 and 9 volts was marginal. I didn't have time to really mess around with components so you might be able to bring out the best with some tweaks. It sounded great as is, two of these together might give you a gain monster of a circuit.
  Please let me know if you find improvements for this, I still have it on the breadboard and plan on trying a few things when I have time.
  Thanks, Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 26, 2007, 11:14:54 PM
  Dano, I forgot to add, I tried 6112 and 6021 tubes and the sounded horrible. That's all.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 26, 2007, 11:34:04 PM
give those 6021 to me if they are horrible ;)
just kidding, I'm looking to get them for a while
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 27, 2007, 07:32:40 AM
I got some 6021A I might make this in a minute  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 27, 2007, 08:14:28 AM
he said they are horrible, so you too should give me yours :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 27, 2007, 09:12:39 AM
Why would I go and do that Bane? I will breadboard it for soemthing to do and tweak it a little for kicks, I have 8 MOS 6021A's dated 6-1958 Muhaha they are for my nano clone ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 27, 2007, 09:18:18 AM
bummer :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 27, 2007, 09:56:04 AM
I know where there are more for cheap money.  PM me if you want to know more mate
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 27, 2007, 10:51:39 AM
you've got a PM :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 27, 2007, 11:50:29 PM
hehehe...I just meant they didn't sound good in this circuit as is. I'm sure with a little tweaking they can sound good too.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: col on December 30, 2007, 11:22:46 AM
This looks interesting. Can you use the standard 1/4 watt resistors or do you need higher rated ones due to the amount of current this is drawing? Has anyone measured how much current it draws in total? Also, would chaining two or more produce an overdrive?
I have an old Babani book that has a valve compressor schematic using 2 12AX7s but it needs at least 100v. I wonder if it would work using 2 12AU7s and 12v.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 30, 2007, 05:06:25 PM
  1/4 watt resistors worked fine for me. This thing burns through batteries, use a power supply/wall wart if you have one.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on December 30, 2007, 06:36:17 PM
This looks interesting. Can you use the standard 1/4 watt resistors or do you need higher rated ones due to the amount of current this is drawing? Has anyone measured how much current it draws in total? Also, would chaining two or more produce an overdrive?
I have an old Babani book that has a valve compressor schematic using 2 12AX7s but it needs at least 100v. I wonder if it would work using 2 12AU7s and 12v.

Hmmmm did you say valve compressor, feel free to e-mail me a copy of the schem ;)  PM for my e-mail address I will ofcourse be forever greatful
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on December 30, 2007, 09:44:25 PM
[quote author=col link=topic=63479.msg504405#msg504405 date=1199031766
I have an old Babani book that has a valve compressor schematic using 2 12AX7s but it needs at least 100v. I wonder if it would work using 2 12AU7s and 12v.
[/quote]

I doubt it, doesn't seem reasonable to me that 12au7 which has much less gain will work even close to 12ax7 under 10 or more times less voltage.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 02, 2008, 02:18:21 PM
  No, I didn't change anything except the pinout and voltage. I thought it sounded best at 7 volts, but the difference between 7 and 9 volts was marginal. I didn't have time to really mess around with components so you might be able to bring out the best with some tweaks. It sounded great as is, two of these together might give you a gain monster of a circuit.
  Please let me know if you find improvements for this, I still have it on the breadboard and plan on trying a few things when I have time.
  Thanks, Jered

I did a bit of searching and found some 6111's for 7 dollars at tubesandmore.com.

Have a few on order now, I can't wait to start tweaking with this new tube.

(http://www.tubecollector.org/main/6111.jpg)

On a related note, I dug up the datasheet for the 6111, and as it was designed for missles and aircraft, the datasheet says "For Operation at Altitudes up to 60,000 Feet" . Never saw that spec before :)

6011 Datasheet found here for anyone who is interested: http://frank.pocnet.net/sheets/079/6/6111.pdf (http://frank.pocnet.net/sheets/079/6/6111.pdf)

<edit: also found a potentially great way to mount those flying lead wires: use an 8-pin DIP socket as seen here: http://www.geocities.com/koalavilla/images/audio/pencil_pre_10.jpg (http://www.geocities.com/koalavilla/images/audio/pencil_pre_10.jpg) >
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 02, 2008, 02:34:08 PM
<edit: also found a potentially great way to mount those flying lead wires: use an 8-pin DIP socket as seen here: http://www.geocities.com/koalavilla/images/audio/pencil_pre_10.jpg (http://www.geocities.com/koalavilla/images/audio/pencil_pre_10.jpg) >


cool ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 02, 2008, 04:22:36 PM
Wow, those 6111's are TINY! I might have to try that after I've built the 12AU7 version (tubes should be here any day :icon_mrgreen: )

Has anyone tried a two tube version yet? If so, would you mind providing wiring advice? I would like to try it, but my simple mind comes up with stupid ideas like making two entire circuits, running them in series and using dual gang pots to control both at once. Yeah.. I'm a newb.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 05, 2008, 04:36:19 PM
Wow, those 6111's are TINY! I might have to try that after I've built the 12AU7 version (tubes should be here any day :icon_mrgreen: )

Has anyone tried a two tube version yet? If so, would you mind providing wiring advice? I would like to try it, but my simple mind comes up with stupid ideas like making two entire circuits, running them in series and using dual gang pots to control both at once. Yeah.. I'm a newb.

here's a rough, unverified splice of the schematic showing two tube stages:

(http://www.beavisaudio.com/Projects/ValveCaster/twincaster.gif)

The 6111's arrived today, smaller than I thought!

(http://www.beavisaudio.com/Projects/ValveCaster/6111.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 05, 2008, 04:41:13 PM
So with the added gain stage there is more gain?

Do you have full layout?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 05, 2008, 05:15:23 PM
im assuming r3 goes to 9v?

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on January 06, 2008, 11:55:06 AM
im assuming r3 goes to 9v?

Zach

Its a safe bet that R3 goes to +9V as the plate would get no DC otherwise as the connection to V1A is de-coupled with a cap (C3) so only AC gets through there.

Looking at it I'd probably loose the first gain control, also has anyone worked out the loads lines or where the bias is set on these?  I know its only at 9volts but it would be interesting to see where they are operating within there range
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Isaiah on January 06, 2008, 02:31:08 PM
Surely C3 needs to connect to pin number 2 on the 2nd 12AU7, doesn't it?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MetalGod on January 06, 2008, 02:44:05 PM
Surely C3 needs to connect to pin number 2 on the 2nd 12AU7, doesn't it?

yep, looks like a drawing mistake.

I'm interested now, found some 6111s and gonna try to find some 6112s (I'm sure they can be made to sound good)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on January 06, 2008, 02:49:35 PM
I think that someone needs to re-draw it as the C an R numbers are repeating where its been copies and pasted.  I am not going to do it as I am not building it but someone with some time could ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 06, 2008, 03:41:38 PM
Regarding the schemo....That's just a rough splice showing the OP where to start. I wouldn't build off that :)

I tried two 6111's in a row last night on the breadboard, it drew too much current for my puny little 9vDC wall wart so I can't comment yet on how two in a row sound. I would hazard a guess that it would be quite noisy and may sound farty unless the gain is adjusted for each stage.

With a single 6111 it sounds pretty good, but I think the heater voltage is going to need to be kept to under 6.3v to avoid burning out the 6111. The little buggers get HOT by the way.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 06, 2008, 06:02:39 PM
Thanks for the diagram Dano :)

I decided to put a SHO-like booster in front of the tube boost, hopefully to attain a little bit of that "hot signal into tube pre-amp" sound -- I have the circuit perfed, but I'm still waiting on damn slow valve delivery before I can test it out and attempt to tune for the sound I'm after.

This experimentation is FUN  :icon_mrgreen: ...though yesterday my girlfriend finally commented on the quickly growing pile of circuits in my home studio :-\
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 06, 2008, 06:53:04 PM
I've been following this thread for some days now. Very, very interesting. Thanks for sharing Dano! I'm just waiting for you guys to come up with a final multi-verified circuit here, and THEN I'll build one too.  ;D My knowledge of tubes is too limited yet, but this looks like what might become a nice entry point into the valve-realm for many people.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: idiot savant on January 06, 2008, 07:15:10 PM
Neat thread Dano, and a neat design.

I really think there could be a whole lot more submini tube designs around. I' have a couple ideas ready for testing around the old Raytheon CK series tubes. they are mostly pentodes, but you can find the odd triode too. I'm planning a small 65mW all tube amp using a 5672, and a 5678 60-ish volt B+. the only real problem with 'em is the unusually high plate load required. the 5672 needs something like 20k, but Fred Nachbaur's "baby bear" using a 533ax would need 80k to get its 1.8mW; but could realistically run off of battery power(only drawing around 32-ish mA).

have a look at these submini monsters for ideas:

http://www.dogstar.dantimax.dk/tubestuf/gallery4.htm

scroll down to the "baby bear" using those teeny tubes even smaller that the 6111's and 6021's

as well as:

http://amps.zugster.net/

the submini section is really good!

 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 06, 2008, 07:57:35 PM
Here's the updated schematic, this one includes the pin numbers for the 6111 in addition to the 12AU7. I've built and verified both.

(http://www.beavisaudio.com/Projects/ValveCaster/ValvecasterSchematicRevB.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: earthtonesaudio on January 06, 2008, 08:28:24 PM
This is really helping me to better understand tubes, so thanks for sharing the knowledge!

So can this circuit do clean (or near-clean) boost?  And would it be possible to use both triodes in push-pull type configuration at such a low voltage?

I've been getting my micro-tube-effect education from the Vox Valvetronix and forum member Brett so far, for the most part.  Thread here:
http://www.diystompboxes.com/smfforum/index.php?topic=64053.msg505674#msg505674
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ambulancevoice on January 06, 2008, 08:33:13 PM
i have an idea
what if, you use a 12ax7 as the main tube, and a 6111 wired as output clipping diodes?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 07, 2008, 05:54:09 AM
I'm not really very knowledgeable about biasing tubes, but I suspect using an AT7 or AX7 will require resistor value changes.

Just a few thoughts from someone who knows even less;

Would it not be possible to put in a trimpot in place of the plate resistor for each stage of the triode for biasing purposes ?
It would be interesting to be able to use the ax7, au7 and ay7 since they are relatively abundant. And maybe running the cicuit at 18 volts ? As far as I know the 12ax7 is supposed to have a plate voltage of 100, but I guess at least something will happen even at as little as 18 volts ?

And another question; are these triodes self biasing in a circuit like this ?

Maybe it's time for a sub forum for high voltage stomp box building ? With the proper warnings and disclaimers posted in front I guess such a forum could become a valuable addition to this site and a great learning resource and symposium for further experimentation.

Here's a resource for those (like me) who need to learn some triode fundamentals:

http://www.angelfire.com/electronic/funwithtubes/Basics_04_Triodes.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on January 07, 2008, 06:38:40 AM
Maybe it's time for a sub forum for high voltage stomp box building ? With the proper warnings and disclaimers posted in front I guess such a forum could become a valuable addition to this site and a great learning resource and symposium for further experimentation.

not a bad idea, there is a forum dedicated to valve stuff www.ax84.com (http://www.ax84.com) springs to mind there are others though ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 07, 2008, 06:52:52 AM
Hey John, yeah I've seen a few (the one you mentioned, and also the great 18watt.com site and others), but I kind of like it here. And we would also keep the main focus on stomp box related stuff instead of going into tube amps which I guess is a bit outside the scope of this site. Hey Aron, how about it ? "Building your own high voltage stomp box" ?  ::) Sorry, I'm drifting off topic. Back to Dano and this great little booster.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 07, 2008, 07:39:40 AM
Hi
I'm just guessing, but I notice that the 12AU7 has low internal resistance.  Only 10 to 15K, compared with 60 to 80k in the 12AX7. Given the low gain of both devices at these voltages, the low internal losses of the 12AU7 might help this critter work. A buffer might be useful at the output (e.g. a JFET source follower).

Vox gets reasonable tones from a 12AX7 at 15V in their Valvetronix series, but they use even higher loads (330k).  And, yes, they do have an option that uses both triodes in a push-pull arrangement.

great work  :icon_smile:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 07, 2008, 08:23:20 AM
Vox gets reasonable tones from a 12AX7 at 15V in their Valvetronix series, but they use even higher loads (330k).  And, yes, they do have an option that uses both triodes in a push-pull arrangement.

Isn't that a 12AU7 in vox pedals?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 07, 2008, 09:44:05 AM
My knowledge of tubes and how to use them basically consists of hooking them up according to various schematics and seeing if they work. I'm about 50/50 on the success rate. I've been doing a lot of reading, but 99% of it is still a mystery to me.

Here's a really interesting idea from a guy who used a 6111 for a headphone amp. It uses a 555 and a voltage regulator to get the correct heater voltage and B+: http://headwize.com/ubb/showpage.php?fnum=3&tid=5878 (http://headwize.com/ubb/showpage.php?fnum=3&tid=5878)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 07, 2008, 05:44:00 PM
In the continuing saga of my 6111 submini tube fetish, I tweaked this some more. After some breadboarding and measuring, it was clear that the 9v source in the previous schematic, as it relates to using the 6111, doesn't work well:

- The heaters call for 6.3vDC. At 9 volts on the previous schematic, they aren't going to last too long
- 9v was simply not providing enough boosth. So I bumped the supply up to 12vDC

To get a nice stable 6.3v heater voltage, and to add a little bit more control, I put together a power supply based on the LM317 adjustable voltage regulator. In combination with a 1Kohm pot/trimmer, I can tweak the heaters to as close to 6.3v as I want. I also added R1/C1/C2 to add a bit of noise reduction to the power supply. Note that the LM317 is going to get really hot, so slap a heat sink on it. You can get the 317 at Radio Shack, it's that common. Adjust TR1 to get 6.3v at the 'heater' connection.

Here's the schemo:
(http://www.beavisaudio.com/Projects/ValveCaster/Subcaster.gif)

And a picture on the breadboard:
(http://www.beavisaudio.com/Projects/ValveCaster/SubCaster_bb.jpg)

The end result with this new tweaked design is that it offers a substantial increase in boost over the 9v in/heater design, and the overdrive sounds a lot nicer.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 07, 2008, 06:21:58 PM
Wow, that looks very promising.
Now I just wonder if this booster can be put in a little amp cicuit like this:

(http://i47.photobucket.com/albums/f191/krinor/Rubywithtriode.jpg)

Is it this simple, or am I missing something ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 07, 2008, 07:08:33 PM
Wow, that looks very promising.
Now I just wonder if this booster can be put in a little amp cicuit like this:

(http://i47.photobucket.com/albums/f191/krinor/Rubywithtriode.jpg)

Is it this simple, or am I missing something ?

I've had stability issues trying exactly that type of schematic when the gain of the tube stage is at max and you max the gain on the 386. Starts to oscillate pretty bad. If you keep the gain lowered on the tube pre-amp, and adjust the 386 gain to taste, it should work. My breadboard tests with the 6111 and JRC386 were disappointing sound-wise.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 07, 2008, 07:14:03 PM
Dano, what tube are you using in that Tube Cricket of yours ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 07, 2008, 07:18:02 PM
Dano, what tube are you using in that Tube Cricket of yours ?

That's a 12AU7.

Let me dig up the schemo.


<edit: here ya go!>
http://www.beavisaudio.com/Projects/TubeCricket/TubeCricket_Final_2008.gif (http://www.beavisaudio.com/Projects/TubeCricket/TubeCricket_Final_2008.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 07, 2008, 07:28:49 PM
That's a 12AU7.

I was asuming that.  :icon_wink:

Let me dig up the schemo.

Please do!

I'm thinking about maybe building a bridged thing with a tube in front. I'm not after the overdrive at all. I'd rather like a clean amp with a fixed gain (R2k2).

Edit:

Thanks! You've made me a very happy man!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 07, 2008, 08:27:02 PM
Dano, what tube are you using in that Tube Cricket of yours ?

That's a 12AU7.

Let me dig up the schemo.


<edit: here ya go!>
http://www.beavisaudio.com/Projects/TubeCricket/TubeCricket_Final_2008.gif (http://www.beavisaudio.com/Projects/TubeCricket/TubeCricket_Final_2008.gif)
When is the kit coming out? I have been waiting forver for it
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ambulancevoice on January 08, 2008, 02:27:45 AM
is there any kind of socket for the 6111?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 08, 2008, 08:11:18 AM
yeah, I saw one on eBay for 7$ a piece, those are very small 8 pin sockets. You can use 8 pin DIL IC socket for this too (see dano's post on the first page)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 10, 2008, 07:28:00 PM
Here's mine:

(http://i47.photobucket.com/albums/f191/krinor/ValveCaster3.jpg)

I built it in one of those gorgeous boxes from Pedalenclosures.
This is the point-to-point version. Did anyone else build from that layout ? Well now it's verified by me at least.
What a great little circuit. Thanks for posting this Dano!
I can see many applications for this one. It would probably be a nice building block for more complicated projects.
It is a bit "dark" sounding, meaning it has a lot of bass content (at least with my SG). How could this be fixed ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 10, 2008, 07:56:30 PM
Did you use the "full" layout I posted?

How does it sound? Sound-clips?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 10, 2008, 08:15:41 PM
No I put a simple on/off switch in it. I wanted to hear it before installing a true bypass switch.
It sounds very good. Being absolutely subjective and esoteric I can tell you that it adds warmth, character and a vintage vibe to your tone. This tells you nothing of course, but you probably get the picture anyhow. Build it yourself. You won't be dissapointed. With some frequenzy tweaking I hope to get some of the rather abundant bass content to behave a bit.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on January 10, 2008, 08:48:15 PM
Here's mine:

(http://i47.photobucket.com/albums/f191/krinor/ValveCaster3.jpg)

I built it in one of those gorgeous boxes from Pedalenclosures.
This is the point-to-point version. Did anyone else build from that layout ? Well now it's verified by me at least.
What a great little circuit. Thanks for posting this Dano!
I can see many applications for this one. It would probably be a nice building block for more complicated projects.
It is a bit "dark" sounding, meaning it has a lot of bass content (at least with my SG). How could this be fixed ?

Wow, that is marvelous! What a nice look.

For lowering bass, you could try lowering the value of either the input cap, or the coupling cap between the two tube stages.

Again, really nice job!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on January 10, 2008, 10:06:02 PM
hi.. i worked more...

this is my version... dual overdrive
  :icon_twisted: :icon_twisted: :icon_twisted:


(http://img245.imageshack.us/img245/2676/dsc00003xo6.jpg) (http://imageshack.us)


(http://img245.imageshack.us/img245/5913/fingscreamerprocesoyr6.th.jpg) (http://img245.imageshack.us/my.php?image=fingscreamerprocesoyr6.jpg)
evolution!!!



(http://img406.imageshack.us/img406/1208/fugscreameruq2.th.jpg) (http://img406.imageshack.us/my.php?image=fugscreameruq2.jpg)

http://www.youtube.com/watch?v=AYtpB10U8FM (whit my cell phone)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 10, 2008, 10:33:50 PM
Is that just two of the original ones together? Or is it something new?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Timebutt on January 11, 2008, 01:23:46 AM
Here's mine:

(http://i47.photobucket.com/albums/f191/krinor/ValveCaster3.jpg)

I built it in one of those gorgeous boxes from Pedalenclosures.
This is the point-to-point version. Did anyone else build from that layout ? Well now it's verified by me at least.
What a great little circuit. Thanks for posting this Dano!
I can see many applications for this one. It would probably be a nice building block for more complicated projects.
It is a bit "dark" sounding, meaning it has a lot of bass content (at least with my SG). How could this be fixed ?

Now all we need is a picture with that gorgeous tube lit in the dark!
What tube did you use and just how much does it light up? :)
Lot of bass content, seems usable for bass maybe?

All in all, very nice build, congrats ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 11, 2008, 03:28:06 AM
Wow, both of those pedals look awesome, great work!

What did you use to cut a hole large enough for the tube in the enclosure?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 11, 2008, 06:44:28 AM
Now all we need is a picture with that gorgeous tube lit in the dark!
What tube did you use and just how much does it light up? :)
Lot of bass content, seems usable for bass maybe?

All in all, very nice build, congrats ;)

Thank you. I used a 12AU7.
12xx7's don't really light up much no matter what circuit they're in. But if you like to play in the dark, then you will be able to see a tiny little glow in there. But seriously, it's the sound of these things that matter. My best 6L6's (NOS RCA's) has black glass housings. Can't see anything in there no, but the sound! Simply amazing.
I haven't tried it with a bass yet. Will do. good idea.  :icon_wink:

Wow, both of those pedals look awesome, great work!

What did you use to cut a hole large enough for the tube in the enclosure?

I used a reamer to cut the hole. Reamers are excellent if you have a steady hand. You just bore a little pilot hole and then off you go. Just be sure to stop and check from time to time so that you don't go to far.

Nice build Niopren. Care to share your layout with us ?

Edit: I've done some tests running the circuit at 12V.
Disclaimer: These are my subjective opinions!  :icon_wink:

12AU7: Brand, Tube Amp Doctor. Nice muddy overdrive and sparkling clean tones. Lots of bass content. Has some nice compression.

12AT7: Brand, Tube Amp Doctor. Very nice overdrive. More distorted. A bit more sparkle on clean tones. Less bass content.A little bit more "open" sound with some more midrange. This particular tube sound better than the AU7 in terms of the quality of the overdrive. Where the AU7 sounds like a perfect tube for a blues horn this particular AT7 seems like a better choice for guitar.

12AX7: Brand, Electro Harmonix. Low output. Less gain than the AT7. This tube has been used for about a year. Probably time to discard it.

Conclusion: For that warm and cozy fireside jam, I'd go for the 12AU7. This one drips of honey and makes me want to grab a beer and play harmonica! For everything else I'd use a 12AT7. But that's just me.  :icon_lol:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on January 11, 2008, 08:03:07 AM
Is that just two of the original ones together? Or is it something new?

only two of the original ones together...
one for boost (distortion)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 11, 2008, 08:20:00 AM
Is that just two of the original ones together? Or is it something new?

only two of the original ones together...
one for boost (distortion)



Do you have some AT7's around ?
Maybe you could run a test with that double version of yours?
I'd be happy to hear your opinions on the following setups: a) 2 AT7's, b) One AU7 and one AT7 and c) vice versa.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 11, 2008, 08:50:24 AM
12AX7: Brand, Electro Harmonix. Low output. Less gain than the AT7. This tube has been used for about a year. Probably time to discard it.

preamp tubes usually live much longer than one year...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on January 11, 2008, 09:20:39 AM
Do you have some AT7's around ?
Maybe you could run a test with that double version of yours?
I'd be happy to hear your opinions on the following setups: a) 2 AT7's, b) One AU7 and one AT7 and c) vice versa.


i test the 12at7 in my pedal, and sound take more distortion, but dont like the saturation.
i use 2 12au7, better works in my case
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 11, 2008, 09:21:01 AM
12AX7: Brand, Electro Harmonix. Low output. Less gain than the AT7. This tube has been used for about a year. Probably time to discard it.

preamp tubes usually live much longer than one year...
My mistake. I have played it for one year. But it was not new when I got it. I have another one in my champ. I'll try that one this evening.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: RLBJR65 on January 11, 2008, 11:10:29 AM
If you want longer battery life use 2 - 9 v in parallel.
More head room with 18v ? Try 2 - 9V in series using a center tap for the heater.
(http://www.aronnelson.com/gallery/d/18556-1/Batteries.GIF)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 11, 2008, 11:40:38 AM
If you want longer battery life use 2 - 9 v in parallel.
More head room with 18v ? Try 2 - 9V in series using a center tap for the heater.
(http://www.aronnelson.com/gallery/d/18556-1/Batteries.GIF)



but make sure you run heaters with one battery only, 18V on heaters is no good.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 11, 2008, 12:20:49 PM
Or use a battery for heater power and an 18 Volt power supply for the rest ?

Dano: How about a high voltage version ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 11, 2008, 01:37:42 PM
in that case it would be better to use a 12V regulator for heaters and ditch the battery all together
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Faber on January 11, 2008, 05:31:28 PM
Sweet!  A tube pedal that won't kill a noob (me).  Can't wait to start the build!

A question for niopren, did you duplicate the circuit to make the dual overdrive?  That's what it looks like, I just want to make sure.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 11, 2008, 07:15:16 PM
Sweet!  A tube pedal that won't kill a noob (me).  Can't wait to start the build!

A question for niopren, did you duplicate the circuit to make the dual overdrive?  That's what it looks like, I just want to make sure.

He probably used this one:

(http://www.beavisaudio.com/Projects/ValveCaster/twincaster.gif)



For lowering bass, you could try lowering the value of either the input cap, or the coupling cap between the two tube stages.


I tried changing the 0,47uF input cap to 0,22uF. This cut into to the midrange as well as the bass content and rendered the tone control pretty much useless. I've left it stock now and I've ended up liking it that way.

A footnote though; Wouldn't it be possible to bleed some bass to ground by putting a cap over two of the lugs of the volume control without loosing too much of the mids ?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on January 11, 2008, 11:02:26 PM
Sweet!  A tube pedal that won't kill a noob (me).  Can't wait to start the build!

A question for niopren, did you duplicate the circuit to make the dual overdrive?  That's what it looks like, I just want to make sure.


yes, i build two identical circuit... and wiring the DPDT for one circuit only boost the first circuit.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 11, 2008, 11:52:44 PM
  If you go high voltage, might as well build an amp.  http://www.harmonicappliances.com/powerman/design/pman_full_A.pdf The 6021's sound great at higher voltage. Haven't tried the 6111 or 6112 sub mini's at higher voltage.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 12, 2008, 08:11:39 AM
Hi
with this kind of thought in mind -

Quote
in that case it would be better to use a 12V regulator for heaters and ditch the battery all together

- I built this today :

(http://www.aronnelson.com/gallery/d/18565-1/Triode+triode.jpg)

That's a faily low parts count - hence the pcb was only 2 1/2 x 1 1/2, including the B9a socket  :icon_smile:
My wall-wart is the charger for my 14.4V rechargeable drill, which puts out about 19V.  The 7812 was getting very hot, so I used 3 diodes (denoted Dx*) ahead of it to drop the voltage to about 17V.  With 17V input and 12V output the 7812 wasn't burning me any more.

The results were a very quiet circuit (DC throughout and low gain probably help) and some promising initial results.

Here's some scope output (1V grids) for different tubes and input levels (sine waves):

12AU7, 200mV input
(http://www.aronnelson.com/gallery/d/18566-1/12au7_200mV_1Vunits_small.jpg)

12AU7, 500mV input
(http://www.aronnelson.com/gallery/d/18568-1/12au7_500mV_1Vunits_small.jpg)

12U7 (low voltage dual triode, built for car radios etc, pin for pin compatible with 12A*7s), 200mV input
(http://www.aronnelson.com/gallery/d/18570-1/12u7_200mV_1Vunits_small.jpg)

12AX7, 200mV input
(http://www.aronnelson.com/gallery/d/18572-1/12ax7_200mV_1Vunits_small.jpg)

As you can see, the 12AX7 doesn't have much gain and is already clipping with 200mV of input. 
But the 12AU7 manages about 6V p-p of output (gain of 30) and seems to work very well.  Clipping is at just about the right amount of input (200mV p-p is about a fresh plucked string and 500mV a chord).  Both sides of the output started to clip at about 1V p-p input, and the output got fairly square at about 2V p-p.  So I think it will break up well with someboost in front.

I'll post some MP3s tomorrow, and try some more variations - maybe a small resistor on the cathode and a larger plate resistor on the second triode ?
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: RLBJR65 on January 12, 2008, 08:39:40 AM
If you want longer battery life use 2 - 9 v in parallel.
More head room with 18v ? Try 2 - 9V in series using a center tap for the heater.
(http://www.aronnelson.com/gallery/d/18556-1/Batteries.GIF)



but make sure you run heaters with one battery only, 18V on heaters is no good.

Yes 18V on the heaters would be very bad! Guess I should have noted the 5 / 3 on the 18V pic is the heater connection as related to Dano schem.

It was just a suggestion to add a bit of room and still keep it a simple low voltage project as it was intended to be.

  If you go high voltage, might as well build an amp.  http://www.harmonicappliances.com/powerman/design/pman_full_A.pdf The 6021's sound great at higher voltage. Haven't tried the 6111 or 6112 sub mini's at higher voltage.
  Jered
Yep!

Nice work Brett!
I was going to recommend the 12U7. There are tons of used and NOS 12U7 around don't know of any manufacturers making new ones though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 13, 2008, 06:38:37 AM
Hi
here is a clip.  Please excuse the playing (nerves).

First part is clean (some breakup due to overloading the sound card), then the same riff played through the Triode triode (with a little boost), then a few chords (Triode triode, no boost), then the riff again, same as before, just played "harder".  It's a bit hard to pick up in the clip, but there's a reasonable amount of difference between the second and fourth parts, and the circuit responds quite a lot to playing style and "attack".

http://www.aronnelson.com/gallery/v/BinOfBrett/Triode+triode+clean+-+boost1+soft+-+boost2_less+-+boost+2+hard+.mp3.html (http://www.aronnelson.com/gallery/v/BinOfBrett/Triode+triode+clean+-+boost1+soft+-+boost2_less+-+boost+2+hard+.mp3.html)

With or without boost, I reckon this is a great little circuit.  Although most of my amps have tube preamps and are dirty, I would still use this as an extra valve stage.  It has a feel of its own.  It's a bit like a low gain pre-amp (e.g. the low gain channel in my Marshall JTM60), but a bit different, too.  Very crisp.

I think it would be an excellent front end for many solid state amps, offering pleasant compression and distortion.

Maybe to temper the highs, you could add some high frequency bypass caps in parallel with the plate resistors.  About 47pF would be right for the 470k resistor, and 100pF for the 220k resistor.  Also, the output is so high that a 5:1 voltage divider (e.g. 470k:100k) could be put ahead of the output pot.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 13, 2008, 05:50:29 PM
Possible improvement, depending on context:

I note that the original schematic and layout specify that the triode at pins 1-3 be used for the voltage gain stage, and 6-8 for the follower.

This isn't usually the best way to do it with a 12A*7.  With battery power or regulated DC going through the heaters, it doesn't matter which triode you use in which position, but if you're using AC or less-than-pristine DC, the triode at pins 6-8 will be quieter, due to the location of the heater pins on the tube.  (You can find mention of this in the data sheets on many 12A*7 series tubes.)

Just thought I'd throw that out there, since this design seems to be giving rise to a lot of variations, and some of them might benefit from swapping the triodes.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 13, 2008, 06:27:21 PM
So, put simple what you're saying is that it might be better to use pins 1-3 for the follower and pins 6-8 for the gain stage ?
Will there be a noticable aural difference in such a low voltage circuit ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 13, 2008, 07:52:12 PM
It definately matters for circuits with AC heating and high gain, such as the Real McTube.

Any of the all-DC designs are ok regardless of order.

By the way, the Triode triode has plenty of gain in both triodes, so it's two gain stages, not a gain stage and a follower.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 13, 2008, 08:17:48 PM
So, put simple what you're saying is that it might be better to use pins 1-3 for the follower and pins 6-8 for the gain stage ?
Exactly.
Will there be a noticable aural difference in such a low voltage circuit ?
If you're using AC or rectified AC for the filaments (or a hummy DC wall wart), hum will be reduced by using 6-8.  How audible it will be depends on the circumstances.  If you used shielded and/or twisted pair cabling for both signal and heaters, and approximated star grounding, it should be quiet enough that you'll notice the difference.  If you did a bad job wiring it, and you've got a noisy fuzz feeding it signal, I'm sure you'd never know one way or the other.  It's not a big deal, and it's a total non-issue in any circuit using clean DC for the filaments, I just mentioned it because few circuit tricks require zero materials and have zero downside, but I like using those few that do exist.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 13, 2008, 08:29:51 PM
By the way, the Triode triode has plenty of gain in both triodes, so it's two gain stages, not a gain stage and a follower.

D'oh!  I mis-remembered the schematic.  I hereby renounce my use of the word "follower" in my earlier post.  Everything else still applies, however.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 14, 2008, 04:45:30 AM
So, put simple what you're saying is that it might be better to use pins 1-3 for the follower and pins 6-8 for the gain stage ?
Exactly.
Will there be a noticable aural difference in such a low voltage circuit ?
If you're using AC or rectified AC for the filaments (or a hummy DC wall wart), hum will be reduced by using 6-8.  How audible it will be depends on the circumstances.  If you used shielded and/or twisted pair cabling for both signal and heaters, and approximated star grounding, it should be quiet enough that you'll notice the difference.  If you did a bad job wiring it, and you've got a noisy fuzz feeding it signal, I'm sure you'd never know one way or the other.  It's not a big deal, and it's a total non-issue in any circuit using clean DC for the filaments, I just mentioned it because few circuit tricks require zero materials and have zero downside, but I like using those few that do exist.

Thanks for sharing. My build seems quiet enough, but I'll try these tricks in the next one I make and see if it gets even better.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on January 14, 2008, 12:04:23 PM
Great job Brett! The pictures you made with your scope show the 12au7 and 12u7 looking very similar. Any sound differences?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 14, 2008, 12:17:57 PM
There are tons of used and NOS 12U7 around don't know of any manufacturers making new ones though.

where? :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 14, 2008, 08:34:53 PM
Hi
Quote
The pictures you made with your scope show the 12au7 and 12u7 looking very similar. Any sound differences?

The 12U7 is definately a softer, cleaner tone.  Even when boosted fairly hard, the 12U7 was mild.  The 12AU7 broke up much earlier and harsher. 

It's probably a bad analogy, but I was thinking that the 12U7 had a lighter, overdrivish, Fendery feel, while the 12AU7 is a dirtier, more Marshally tone. (Old Marshall, like an 18 watter or JTM, not a JCM or high-gain Marshall)

cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: RLBJR65 on January 15, 2008, 07:11:00 AM
where? :)


I have a surpluss store near me that has a box of them. The problem is that I don't think they would go and look if you called etc.
If you want some let me know I can go in a couple of weeks. The last one I bought was $4.00.
I just Googled "12U7 tube" and found 2 places on the first page :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on January 15, 2008, 10:37:47 AM
"The 12U7 is definately a softer, cleaner tone.  Even when boosted fairly hard, the 12U7 was mild.  The 12AU7 broke up much earlier and harsher. "

Awesome. Thanks for the info. I have some 12au7 tubes already and 6011's on the way to play with on these low voltage type designs. I will get some 12u7's also.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Lonzo on January 17, 2008, 11:43:13 PM
What a great looking circuit; I've been trying to get into a tube build for some time. Thanks for sharing circuit.

Dose anyone have any thoughts on the affect of eliminating the tone control?  Would there be some additional gain obtained as a result? 

Thanks for your thoughts,
Lonzo

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 18, 2008, 03:30:24 AM
I don't think it makes such a big difference. At full tilt there is a tiny bit more gain than when it is turned all the way down. This tone control works fine, but it's not that effective. Personally I leave mine at about 1 o'clock. If your point is that you want to save some space and leave out a pot, you might still want to shape your tone by making a preset treble bleed. For instance you could replace the pot with a 50k resistor (to put it in the middle position). Or put sockets in and experiment with different values until you find the tone you like.

Good luck. This circuit is very easy to make and a lot of fun too. Use a 12 volt wall wart!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Faber on January 21, 2008, 09:42:58 PM
I was thinking about this circuit and I came up with something for someone who built this for a second time, or someone who is WAY too ambitious (like me).

Okay, so I looked at the argument about 12V vs 9V and I was thinking about using a 12.6V transformer and a full wave rectifier TUBE.  Now, this might be too bulky for such a small pedal, but it would kinda be more like a real tube amp...  Maybe I'm just crazy... errrr... maybe I'm crazier than I thought I was!

Didn't I also see something about the tube heaters needing (or wanting) 12.6V???

Not to mention, 2 TUBES LIGHTING UP!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 21, 2008, 11:30:28 PM
As per tube recto, there would be no need, except for look, as a tube recto and diode recto do the exact same thing in this particular situation.

For the 9v and 2 tube argument, I agree. With both heaters + circuit drawing power, this thing is a 9v battery eater. In my pedal, I power by a 12vac wallwart, then rectify internally with diodes.

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 21, 2008, 11:33:03 PM
I was thinking about this circuit and I came up with something for someone who built this for a second time, or someone who is WAY too ambitious (like me).

Okay, so I looked at the argument about 12V vs 9V and I was thinking about using a 12.6V transformer and a full wave rectifier TUBE.  Now, this might be too bulky for such a small pedal, but it would kinda be more like a real tube amp...  Maybe I'm just crazy... errrr... maybe I'm crazier than I thought I was!

Didn't I also see something about the tube heaters needing (or wanting) 12.6V???

Not to mention, 2 TUBES LIGHTING UP!!!

A 12.6v transformer will not give you the voltage you want for the filaments, unless you skip rectification and just use the AC.  If you hook the heaters up in series, anything from 9v to 13v will work, although 9 is pretty low to do the job, and anything over about twelve and a half will reduce tube life.  Something like 11-12 is probably ideal.  If you're hooking up the filaments in parallel, halve those voltages.  A 12.6v transformer produces 12.6 VAC, after that goes through a bridge rectifier and hits filter caps, what you end up with is 12.6 * 1.414 volts, less the drop across the rectifier diodes.  In practice, this works out to maybe 16.5-17v, which is high enough to fry the heaters very quickly.  If you use a different rectifier topology, you end up with 12.6 * 0.707 volts (minus losses), which might get you 8 volts, with luck.  Tube diodes have higher internal impedance than silicon, so the voltage drop would be greater, but I really don't think by enough to drop your 16.5-17v to 12.6 or less.

If you want to do use tube-rectified DC for the heaters, you need a transformer in the 7-9v range (or half that if hooking them up in parallel).  Or higher voltage and a regulated power supply.  Do remember to get a bigger transformer, since you'll need to provide the rectifier with heater current, too.

Bear in mind that tube rectification's main mojo (power supply sag) does not apply to Class A circuits, which this one is, so the only benefit you're likely to get for the added expense and bother, will be cosmetic.  If you want to make it more like a tube amp, there are probably better ways of doing that.  You could, for example, use something like a 20k:2k output transformer.  This would cut the output at clipping from close to 9v to a more manageable 0.9v, lower the output impedance, and probably make it sound a bit more like the real deal.  Since you're very ambitious, I'll leave figuring out how to do that as an academic exercise.  It's not hard, and learning is good.  :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Faber on January 22, 2008, 08:04:38 PM
Yeah, I do know that except for the tube lighting up it would be useless...

I am not 100% on the rectifier calculations so that's useful information!!!

So if the heaters are running off of AC, then don't rectify the heater voltage that you need and rectify what you do need...

It's a ridiculous idea, I know...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: machineman on January 23, 2008, 01:35:04 PM
I've built one of these...It's awsome!!! Very very warm.  I put it infront of my effects chain...And I love it!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: petemoore on January 24, 2008, 12:24:51 AM
  Would the heater filament not prefer ~6.3v for longest life?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 24, 2008, 12:40:31 AM
Depends on wiring.

If you go straight off the 9vbattery, yes you are declining tube life no matter what. For best tube life you need 6.3v or 12.6v. 6 or 12 is close enough, b9 is obviously nowhere near either. You either want 6.3 volts across pins 4+5 and 9, or 12.6v between 4 and 5.

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bancika on January 24, 2008, 08:20:06 AM
I don't think that lower heater voltage (like 9V for both heaters) would lower tube life. It would just sound different that it's supposed to.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on January 24, 2008, 11:18:00 AM
"I don't think that lower heater voltage (like 9V for both heaters) would lower tube life. It would just sound different that it's supposed to."

Lower heater voltage is actually worse. From the Tone Lizard,

Look about halfway down the page of this link to see the chart:

http://www.tone-lizard.com/Marshall_Myths.htm


"I would like you to study the diagram below carefully. It is from the book Audio Cyclopedia, by Howard M. Tremaine. It deals with the prospect of running the filament voltage on any tube at other than 100% rated value. The illustration shows that tubes will fail prematurely if the filament voltage is either higher or lower. For maximum tube life, the voltage must be 'right'."

"From the chart above, you should be able to determine that if a tube has a usable life of approximately 6,000 hours with its filament operated at 100% of the rated voltage, the tube's life expectancy is reduced to 1,000 hours just by lowering the filament voltage by 10%. This translates to a 6.3VAC tube being run at approximately 5.67VAC, or the input voltage lowered from 120VAC to approximately 108VAC. Ask your local tube guru if they have read Audio Cyclopedia. However, even 'experts' can disagree on anything and everything. GE published data confirming tube life is decreased substantially by raising the filament voltage, although tube life can be increased by lowering the filament voltage very slightly. The performance of the tube was purported to be more 'even' over its useful life. However, it should be pointed out that the slightly lowered filament voltage GE 'recommends' proportioned to the plate voltage (via your VariacTM) won't make a difference to our ears. People who set their VariacTM to 100VAC are only asking to replace tubes every other month. The GE report also stated that the transconductance of the tube was reduced dramatically, and an audible deterioration in performance was noted when reduced filament voltages were employed. So why bother?"





Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 24, 2008, 05:24:44 PM
There are a lot of different figures on tube life and heater voltage, in part because different tubes respond differently.  Those with thoriated heaters, for example, do well when run at rated voltage for their first 200 hours, then dropped to 95% of full voltage until they approach end of life. http://www.cpii.com/docs/related/22/AB18.pdf  Dropping to 90% of rated voltage after the initial 200 hours may increase filament life to the point that heater failure will be eliminated as a cause of (thoriated) tube failure. http://www.burle.com/cgi-bin/byteserver.pl/pdf/tp202.pdf  Tubes with oxide-based heaters are different.  Power tubes can have their life shortened by running at lower heater voltages, but others often benefit from slightly lower voltages: at 10% above rated voltage, life will be cut by half, at 5%-10% below rated voltage, tube life will be significantly enhanced at the cost of slightly worse performance in various other regards. http://www.pmillett.com/Books/Tomer_1960_Getting_the_Most_Out_of_Vacuum_Tubes.pdf  I suspect that the author cited by the earlier poster was thinking of power tubes when he condemned running tubes at reduced heater voltages, since it is very true with those.

My recommendation would be to never run power tubes at anything but their rated voltage, and to rectify, filter, and regulate that voltage if you're using expensive tubes.  For other types of tubes, if high longevity matters more to you than squeezing every last bit of performance out of it, rectification and filtering are also good, but the target voltage should be 5%-10% below rated value.  Anything lower than 90% of rated value will cause worse performance without enhancing tube life, and may actually shorten life.  Using tube coolers and/or cooling fans will also increase life, often doubling it.

Using 9v in place of 12.6 for heaters is not a great idea from any perspective, in this schematic it has to be considered a matter of convenience rather than good design.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: petemoore on January 24, 2008, 06:10:07 PM
  If you're playing in Timbuktu, carry a spare tenbuck Tube.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 24, 2008, 08:50:47 PM
Why do backflips in order to avoid using a 12V DC wall wart ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 24, 2008, 09:36:36 PM
Why do backflips in order to avoid using a 12V DC wall wart ?

I agree, 12v would be a lot better, no idea why the original design didn't use that (can't read Japanese).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 25, 2008, 12:01:13 AM
Why do backflips in order to avoid using a 12V DC wall wart ?
I agree, 12v would be a lot better, no idea why the original design didn't use that (can't read Japanese).

I'll see if I can do some samples of this circuit at 9v vs. 12v tonight, so long as I can get ProTools 7.4 and OSX 10.4.11 to play friendly.  :icon_evil:

<noob> Perhaps as well as being better for the valve it also will provide a cleaner boost? </noob>
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 25, 2008, 12:05:59 AM
Sounds good, hope you get it working!

I'd say maybe more clean headroom. I can't really hear any discernable difference between 9v and 12v, but my wallet sees the difference between 9v bat and 12v ww. Trust me, go wallwart guys.

Just my $.02 (or if you use 9v batteries, $10/week)


Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MasaRGR on January 25, 2008, 03:52:07 AM
Going back and reading Matsumin's notes, he mentioned that there are lots of schematics and designs for 12v, so he wasn't interested in making another 12v version.

His original goal was to make a simple tube booster that anyone could easily build and if possible, make it 9v, and this was the result. He doesn't know lots of the theory and concepts involved with using vacuum tubes in these type of circuits and that this was an experiment to see if he could just make it work.

He said that on breadboard, he got a more cleaner sound with higher voltages like 12v and 15v and that for people seeking more clean headroom to try higher voltage power supplies.

He got some nice sounds with the 12AT7 tube, but preferred the 12AU7 in this circuit. He tried a 12AX7 but said that it didn't work well at all with this design.

He mentioned that he designed this for single coil pickups and that his humbucker equipped guitars were too boomy.

Hope this helps.

Masa
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 25, 2008, 04:12:00 AM

He mentioned that he designed this for single coil pickups and that his humbucker equipped guitars were too boomy.

Hope this helps.

Masa

Now that makes sense. Maybe it sounds okay with single coils at 9v, but needs 12v to sound good with humbuckers ? I have only used mine with a rather dark sounding SG and a 12v supply. Sounds nice to me.

Thanks for the translations. Could I be so bold as to ask you to please translate the whole article and post it for the benefit of the DIY community ? I know a lot of people would be very gratefull.  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 25, 2008, 04:34:40 AM
He mentioned that he designed this for single coil pickups and that his humbucker equipped guitars were too boomy.

Interesting. To me, it has more of a light OD jangle when I set the 'buckers on my carvin to split (single coil), but the sound when being driven by the full humbucker is still good; a lot more crunch to my ears and I prefer it over the single coil sound. It does do wonders for funk rhythms on my strat though, so long as I keep the gain low  :o

Regarding 12V operation -- does anyone else notice a defined hum when switching to 12v? I know it's not the power supply as I'm using a BBE supacharger and just flicking the 9v/12v DIP switch for that output. My gut feeling is that it's a bias issue... and my n00b guess is that R3 (100k between pin 6 and V+) is responsible for bias?

I dig the sound of this circuit, but I'll wait until someone confirms or denies my guesses regarding 12v hum and bias before replacing the resistor with a pot. 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 25, 2008, 05:23:16 AM
He mentioned that he designed this for single coil pickups and that his humbucker equipped guitars were too boomy.
Regarding 12V operation -- does anyone else notice a defined hum when switching to 12v? I know it's not the power supply as I'm using a BBE supacharger and just flicking the 9v/12v DIP switch for that output. My gut feeling is that it's a bias issue... and my n00b guess is that R3 (100k between pin 6 and V+) is responsible for bias?

I'm using a regulated ac/dc adaptor capable of 500mA. It's switchable between 9 and 12 v. I tried it with everything maxed on the valve caster and the amp turned up loud. There is a subtle hiss at these extreme settings. Switching between 9 and 12 volts does not alter that rather faint hiss in my case. All in all I was actualy surprised at how quiet this circuit was.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: jakenold on January 25, 2008, 05:59:49 AM
Regarding 12V operation -- does anyone else notice a defined hum when switching to 12v? I know it's not the power supply as I'm using a BBE supacharger and just flicking the 9v/12v DIP switch for that output. My gut feeling is that it's a bias issue... and my n00b guess is that R3 (100k between pin 6 and V+) is responsible for bias?

I dig the sound of this circuit, but I'll wait until someone confirms or denies my guesses regarding 12v hum and bias before replacing the resistor with a pot. 

Now you have rewired the heaters for 12V operation, right? If you're running them in parallel (6,3V operation) at 12V, that can't be good.

Jake
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MasaRGR on January 25, 2008, 06:28:25 AM
Thanks for the translations. Could I be so bold as to ask you to please translate the whole article and post it for the benefit of the DIY community ? I know a lot of people would be very gratefull.  :icon_wink:

You're very welcome.

As for translating the rest, most of it isn't of much use as he makes lots of references to some obscure Japanese magazines and texts, and the rest is just some "shoulda/woulda" kind of brainstorming.

A few things that may be of interest - he said that he bought a tube socket with pcb pins - but the pins weren't sized for his board holes so he had to do a lot of bending and twisting to get the socket mounted. One thought he had was to just use a regular tube socket and attach the components directly to the base of the socket (ala DanO) or use a small turret board or lag board. He used some vintage ceramic caps in C1 and C4 as well as an oil capacitor for some extra "mojo". He did say that his layout wasn't too well thought out as he would have to remove knobs and unscrew the pots to get access to the tube  ;D

He did give big props to Bancika's DIY layout creator and mentioned how much he appreciated the upgraded version.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DryRoasted on January 25, 2008, 06:56:04 AM
Built mine!  Will only work with 12V though (I'm using a 12AT7, may or may not have anything to do with it).  Sounds very very good.  just for jollys, turn the vol and gain up full and crank out the riff to Smoke on the water! 

I tried an AX7 that I had lying around and that sounds different still, not too bad, quite useable in fact but just not as clean as the other.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on January 25, 2008, 06:58:29 AM
I'm using a regulated ac/dc adaptor capable of 500mA. It's switchable between 9 and 12 v. I tried it with everything maxed on the valve caster and the amp turned up loud. There is a subtle hiss at these extreme settings. Switching between 9 and 12 volts does not alter that rather faint hiss in my case. All in all I was actualy surprised at how quiet this circuit was.

Damn. Exactly the same power situation as me, but yours doesn't make the odd noise.

Quote from: Jake
Now you have rewired the heaters for 12V operation, right? If you're running them in parallel (6,3V operation) at 12V, that can't be good.
If I had half a clue what that means, I'd respond appropriately...  ???  :icon_eek:  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 25, 2008, 07:41:40 AM
Thanks for the translations. Could I be so bold as to ask you to please translate the whole article and post it for the benefit of the DIY community ? I know a lot of people would be very gratefull.  :icon_wink:

You're very welcome.

As for translating the rest, most of it isn't of much use as he makes lots of references to some obscure Japanese magazines and texts, and the rest is just some "shoulda/woulda" kind of brainstorming.

A few things that may be of interest - he said that he bought a tube socket with pcb pins - but the pins weren't sized for his board holes so he had to do a lot of bending and twisting to get the socket mounted. One thought he had was to just use a regular tube socket and attach the components directly to the base of the socket (ala DanO) or use a small turret board or lag board. He used some vintage ceramic caps in C1 and C4 as well as an oil capacitor for some extra "mojo". He did say that his layout wasn't too well thought out as he would have to remove knobs and unscrew the pots to get access to the tube  ;D

He did give big props to Bancika's DIY layout creator and mentioned how much he appreciated the upgraded version.


There are so much incredible information on hi-fi and other such things in Japanese. I think I need to learn some of that language eventually! Right now I can only look at photos and sometimes I'm lucky enough to accidetally stumble across something that turns out to be a link to a schematic. Ha,ha. Please share more goodies with us if you come across something that might be of interest here.  :icon_wink:

I'm using a regulated ac/dc adaptor capable of 500mA. It's switchable between 9 and 12 v. I tried it with everything maxed on the valve caster and the amp turned up loud. There is a subtle hiss at these extreme settings. Switching between 9 and 12 volts does not alter that rather faint hiss in my case. All in all I was actualy surprised at how quiet this circuit was.

Damn. Exactly the same power situation as me, but yours doesn't make the odd noise.

Quote from: Jake
Now you have rewired the heaters for 12V operation, right? If you're running them in parallel (6,3V operation) at 12V, that can't be good.
If I had half a clue what that means, I'd respond appropriately...  ???  :icon_eek:  ???

If he was running the heaters in parallel he would be sending 12 volts to pins 4 and 5 and use pin 9 for ground, right ? In this case pin 5 gets 12 volts and pin 4 goes to ground. Pin 9 is not used.

Are you suggesting that there should be a separate 6.3 volt heater circuit  on this one ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: niopren on January 25, 2008, 08:40:33 AM
If properly understanding the above, the 12.6 V could be connected without any changes, according to the wiring of this image?

[/quote]
(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCasterWiring.gif)
[/quote]

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 25, 2008, 08:58:41 AM

this is my version... dual overdrive

(http://img245.imageshack.us/img245/2676/dsc00003xo6.jpg) (http://imageshack.us)


Niopren, or Dano, is it possible to have a layout for the dual valve schematic?! I'd like to have one as this one above for one valve only...Thank you...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 25, 2008, 09:04:37 AM
Hi
RE: dual tubes
My "Triode triode" circuit, which is similar, gave plenty of gain and distortion with just 1 12AU7 tube. (soundclip posted above)
If you want monster gain, just use a booster in front.

RE: series and parallel heater wiring

For those new to the 12**7 series and similar tubes, the element connects 4 and 9 and 9 and 5.
Serial connection runs from 4 thru 9 to 5, with 4 at 12.6V and 5 grounded. ( Or 5 at 12.6 V and 4 grounded).
Parralel runs from 4 to 9 AND 5 to 9, with 4 and 5 at 6.3 V, and 9 grounded.

For a circuit such as this I recommend using DC for the filaments.  Even better if it's a DC wall, wart, so that AC never gets near the circuit at all.  This is because those hum-inducing AC currents in heaters are so large (hundreds of mA) relative to the signal (thousandths of a mA) that hum will appear if your wiring setup is less than perfect.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ItZaLLgOOd on January 25, 2008, 09:11:14 AM
Has anyone tried clipping diodes yet?  I already use a tube amp and I am mainly looking for a tube distortion type of pedal.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on January 25, 2008, 11:17:22 AM

this is my version... dual overdrive

(http://img245.imageshack.us/img245/2676/dsc00003xo6.jpg) (http://imageshack.us)


Niopren, or Dano, is it possible to have a layout for the dual valve schematic?! I'd like to have one as this one above for one valve only...Thank you...

The schematic for the dual version is posted on page 4 of this thread.

EDIT: Er... sorry. I didn't read that question properly. You probablu know where the schmo is.

Hi
RE: dual tubes
My "Triode triode" circuit, which is similar, gave plenty of gain and distortion with just 1 12AU7 tube. (soundclip posted above)
If you want monster gain, just use a booster in front.

RE: series and parallel heater wiring

For those new to the 12**7 series and similar tubes, the element connects 4 and 9 and 9 and 5.
Serial connection runs from 4 thru 9 to 5, with 4 at 12.6V and 5 grounded. ( Or 5 at 12.6 V and 4 grounded).
Parralel runs from 4 to 9 AND 5 to 9, with 4 and 5 at 6.3 V, and 9 grounded.

For a circuit such as this I recommend using DC for the filaments.  Even better if it's a DC wall, wart, so that AC never gets near the circuit at all.  This is because those hum-inducing AC currents in heaters are so large (hundreds of mA) relative to the signal (thousandths of a mA) that hum will appear if your wiring setup is less than perfect.
cheers


Thanks Brett! This thread is becoming a nice little tubenoob primer  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 25, 2008, 02:20:29 PM
Yes, Krinor, I'd like to have a LAYOUT based on the schem we have some ages ago... ;)


EDIT: ooops, I meant "Pages"...This darn sylicon keyboard... :-\
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 25, 2008, 03:20:23 PM
Has anyone tried clipping diodes yet?  I already use a tube amp and I am mainly looking for a tube distortion type of pedal.

Can't say that I've ever used clipping diodes in a tube circuit.  Aside from extreme fuzz effects like the early germanium stuff, I think of diodes as a way to get around the fact that bipolar transistors often sound like crap when driven to clipping.  With the lovely sound of clipping tubes, I'm not sure why you'd want diodes, unless you were wanting to play a lot of "Satisfaction" or "In-A-Gadda-Da-Vida."
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ItZaLLgOOd on January 25, 2008, 03:51:41 PM
I was curious about clipping diodes and tubes.  I was under the impression that this project didn't clip a whole lot.  I was looking for something with more distortion but "In-A-Gadda" was not the direction I wanted to head.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 25, 2008, 05:06:51 PM
Well, with a reported gain of around 30, and output that's somewhere between 8 and 11 volts (depending on whether you're doing it with 9 volts or 12), the most you'd need to drive it into clipping would be 11v/30 = 0.37 volts.  If that isn't enough gain for your pickups to drive it into clipping, more gain could easily be added -- switching from a 12AU7 to a 12AT7 might work, or you could just stick a single JFET in front of it and pick up additional gain of 4-5, boosting total gain to 120-150.

(Some people might cringe at the idea of "polluting" a tube effect with a solid state device, but I think that JFETs are just about perfect for this particular use.)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: earthtonesaudio on January 25, 2008, 08:09:50 PM
What about tube diode clipping?  I have a few old 6AL5 tubes (twin diodes) lying around, but I don't know much about tubes in general.  You could do the same thing with tube diodes as you normally do with solid state, but I don't know how useful it would be.  Some things to consider:

-Would tube diodes clip like we are talking about here, or would the clipping voltage level be way too high? 
-For the 6AL5, the spec sheet says it drops 10 volts per plate... My guess is that would be way too much in a low-voltage effect such as this, but I just thought I'd throw it out there as food for thought.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on January 26, 2008, 11:24:17 AM
A regular diode to ground clipper will work just fine in this circuit. See Marshall JCM900 schematic. Diode and tube distortion in the preamp. Whether that sounds better than just adding more gain at the front, I don't know.
As for tube diode, maybe try it with a AMZ saturation control.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 26, 2008, 07:08:29 PM
Hi
RE clipping.

As I said above, with a tad of boost I got this much clipping.

(http://www.aronnelson.com/gallery/d/18568-1/12au7_500mV_1Vunits_small.jpg)

With lots of boost (to 2V p-p), the output was squarish.  It sounded similar to my JTM60 Marshall when fully cranked on the "vintage" channel. (a tone that's loved my many) Clipping diodes will be much coarser in tone, whether in this circuit or one such as the Distortion +, placed before it. 

As said above, a single JFET booster will do the job of overloading this circuit:

Quote
Well, with a reported gain of around 30, and output that's somewhere between 8 and 11 volts (depending on whether you're doing it with 9 volts or 12), the most you'd need to drive it into clipping would be 11v/30 = 0.37 volts.  If that isn't enough gain for your pickups to drive it into clipping, more gain could easily be added -- switching from a 12AU7 to a 12AT7 might work, or you could just stick a single JFET in front of it and pick up additional gain of 4-5, boosting total gain to 120-150.

cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: petemoore on January 26, 2008, 09:40:41 PM
or you could just stick a single JFET in front of it and pick up additional gain of 4-5, boosting total gain to 120-150.
  Often we do, Jfet 'up front' is oft preferred, not that CMoS or..
  For just getting the signal level up to a point where the next stage or so can start distorting it, some fine Jfet dirt, or Mosfet clean, or...other non-tube active circuit as gain stage certainly makes sense, i
  If the first tube stage is only boosting and not distorting, well, that type of clean or even a touch of fine dirt leaves the subsequent tube stages to be used for producing the actual distorting properties we're looking for.
  Not to say "Don't let any non-tube light distortion introduced by non-tube active in" before tube gets it's chance to distort.
  @9vdc with 12a_7 tube providing boost and distortion, and not much headroom to work with, letting something else to much of the grunt work [many small signal device types bias @9v and sound great]...more tube distortion will be available as well as more output available which could be used for voicing options.
  You could use another tube for that, but with battery, I'd stick to one tube.
  There's probably a sweet spot for input level on the tube, adding preboost at least seems a logical way to find out if it's not preferred.
  First priority for new tube here is to get the right power supplied and see if they light up, a little off isn't bad, and as long as they light up the tube should work, I've run them like that, but between the data sheets and other data, the right voltage for the heaters is always recommended.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 26, 2008, 10:00:37 PM
  Anybody tried 12AV7 in this circuit? I'm going to try it tomorrow and will post my results.
  Guys, if you have a power supply you can use for this, do it. Using batteries, they barely last long enough to do any tweaking. The circuit goes from sounding decent, to degrading quickly, trying to work on tone improvements with batteries for power, in this circuit, is tough.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 26, 2008, 10:06:16 PM
12AV6

IIRC - This tube was built to be driven (I believe in computer systems?)
Has roughly same gain as ax7
Would act the same as ax7 in this circuit if the above is correct

But why not try it, and tell us your results

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 26, 2008, 11:33:51 PM
  For just getting the signal level up to a point where the next stage or so can start distorting it, some fine Jfet dirt, or Mosfet clean, or...other non-tube active circuit as gain stage certainly makes sense, i
  If the first tube stage is only boosting and not distorting, well, that type of clean or even a touch of fine dirt leaves the subsequent tube stages to be used for producing the actual distorting properties we're looking for.

Thanks for elaborating, those were exactly my thoughts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 27, 2008, 01:35:01 AM
  Were you talking to me Zach, about the 12AV6? I'll try it out. I'll have to go get the AV6's from the tube cabinet at the studio, I'll be down there Monday. The AV7's are right in front of me, going to run those first.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on January 27, 2008, 01:44:50 AM
Sorry, meant av7,

Fingers mind and eyes don't always line up after exam week  :icon_biggrin:


Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 27, 2008, 01:51:19 AM
  On the subject of tubes, here's a link to some tubes that have just been collecting dust.
http://www.diystompboxes.com/smfforum/index.php?topic=64670.0
 Take a look, maybe there's some you guys might want.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 30, 2008, 03:51:14 AM
  OK, I had a chance to try out a few more tubes in this circuit. I tried 12AV7, 12AY7, 12AD7, 12BZ7, and 6072. None of which sounded any good. 6111 sub mini's are still my fave. Need to get some 12U7's to try.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: earthtonesaudio on January 30, 2008, 05:09:03 PM
  OK, I had a chance to try out a few more tubes in this circuit. I tried 12AV7, 12AY7, 12AD7, 12BZ7, and 6072. None of which sounded any good. 6111 sub mini's are still my fave. Need to get some 12U7's to try.
  Jered

Did you try those with no other adjustments to the circuit?  Coming from a transistor background, I would think that different tubes would need to be re-biased to sound right.  Or perhaps this doesn't apply with this particular circuit  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on January 30, 2008, 05:52:32 PM
  OK, I had a chance to try out a few more tubes in this circuit. I tried 12AV7, 12AY7, 12AD7, 12BZ7, and 6072. None of which sounded any good. 6111 sub mini's are still my fave. Need to get some 12U7's to try.
  Jered

Did you try those with no other adjustments to the circuit?  Coming from a transistor background, I would think that different tubes would need to be re-biased to sound right.  Or perhaps this doesn't apply with this particular circuit  ???

The same is true of tubes, but the brute force approach is quick and easy.  I'd wager that this circuit, with some adjustments, would sound lovely with a 12AV7 and a 50 volt power supply, but then it would be a very different project.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on January 30, 2008, 07:51:37 PM
Hi
I think that valves with low Ri (internal resistance), and maybe low mu (the sound cows make) will work best.
The 12AU7 is the lowest of the common dual diodes (Ri about 7k, from memory), with the AT7 also fairly low (Ri about 12k ?).  Note the Ri figure is for normal operating voltages (e.g. supply at 150V) and the real internal resistance may be much higher under the conditions in these low voltage circuits.

I'm guessing that low internal resistance in the circuit (ie. at low voltage), as indicated by low Ri (on the datasheet), is the key to getting more electrons to flow at these extra-low voltages.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 01, 2008, 11:15:13 AM
For those that have built this circuit, how well does the gain pot work? It's in a location that controls bias and feedback as well as gain so I was wondering how it "cleans up" well rolled back. Does it get gatey or weird at all? It seems a better place for it would be in between the gain stages like a regular tube pre amp.
Thanks.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DryRoasted on February 01, 2008, 03:20:48 PM
For those that have built this circuit, how well does the gain pot work? It's in a location that controls bias and feedback as well as gain so I was wondering how it "cleans up" well rolled back. Does it get gatey or weird at all? It seems a better place for it would be in between the gain stages like a regular tube pre amp.
Thanks.

The gain pot works very well in my build (using a 12AT7), at min gain I have to drop the guitars vol pot a little to get totally clean boost but the again I have fairly hot humbuckers.  Not gatey or weird at all, very smooth control.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 01, 2008, 03:52:42 PM
For those that have built this circuit, how well does the gain pot work? It's in a location that controls bias and feedback as well as gain so I was wondering how it "cleans up" well rolled back. Does it get gatey or weird at all? It seems a better place for it would be in between the gain stages like a regular tube pre amp.
Thanks.

I am also very satisfied with the gainpot on my build. When cranked it sounds not entirely unlike the sound of a simple class a tube amp at full tilt - even if it is maybe a bit more muddy (?)

Your question is interesting and I hope some of the tube experts will elaborate on the topic. I'd also like to add another question (since this thread is not sticktly on topic anymore anyway): Would it be possible to add a master volume onto the output of a class a amp similar to the master volume in the valve caster circuit ? Maybe we could have some of you tell us more about pot placements in valve circuits in general ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on February 01, 2008, 06:06:15 PM
(The gain pot is) in a location that controls bias and feedback as well as gain.... It seems a better place for it would be in between the gain stages like a regular tube pre amp.
Thanks.

I think that the most flexible arrangement would be to have volume, bias and feedback adjustments for each gain stage, but if you made a normal pre-/amp that way you'd end up with so many controls that it would take ages just to discover all the possible settings, let alone remember which ones you liked.  So you use a lot less controls than that, and decide what sort of flexibility you're most willing to give up.

If you put the pot between stages, you have eliminated the possibility of ever changing the bias or feedback in the first stage; it will always be exactly as warm/cool, and as clean/dirty (for a given volume level) as you've made it.  All you can do is to make it quieter or louder.  Fortnately, this should also let you control clipping of the second stage, assuming you provided enough overall gain.  But you are narrowing down the possible voices of the effect to a certain range.  This isn't necessarily a bad thing.  If clean sounds like a '61 Fender Deluxe's clean, and boosted sounds like a cranked '61 Deluxe, maybe that is exactly what you want.  If nothing else, it eliminates tons of ugly sounding settings that might otherwise have been available.  But if you made it to sound like a '61 Deluxe, and the user happens to hate that tone, they're just outta luck.

If you leave the pot where it is, you CAN change bias and negative feedback along with volume, but you can only change all three at once.  It gives one a wider range of tones to pick from, but it may be that you don't care for most of those tones, and can't arrive at some you'd prefer.  Maybe it now ranges from clean Deluxe, to cranked Marshall 18, to distortion monster created by the gods of metal, and you can no longer get to the cranked Deluxe sound at all.

So it just depends on what you're after.  Every guitarist's ideal setup would probably be a little different.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on February 02, 2008, 07:57:20 AM
Hi
Quote
If you put the pot between stages, you have eliminated the possibility of ever changing the bias or feedback in the first stage; it will always be exactly as warm/cool, and as clean/dirty (for a given volume level) as you've made it.

I'd suggest that you haven't really eliminated the opportunity for a bias change.  It just requires one resistor to be changed, or a trimpot to be adjusted.  And amps have the bias set, so unless there's a problem with every tube amp out there, there's not much of a problem with setting the bias to a "sweet" value and leaving it there.

A small value cathode resistor (1k) seems to work for 12AU7s, so a small resistor (470 ohms) and a trimpot of 1k would seem ideal.  Large cathode resistance (e.g. 10k) is only likely to give low gain, and eliminate much of the "overdrive" effect.  Personally, I would also keep any pot between stages 1 and 2 cranked, so it might as well be wired direct.

Again, this works well, IMO :
(http://www.aronnelson.com/gallery/d/18565-1/Triode+triode.jpg)

Just my 2c.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on February 02, 2008, 04:27:46 PM
Hi
Quote
If you put the pot between stages, you have eliminated the possibility of ever changing the bias or feedback in the first stage; it will always be exactly as warm/cool, and as clean/dirty (for a given volume level) as you've made it.

I'd suggest that you haven't really eliminated the opportunity for a bias change.

Sorry, I guess I was unclear.

You've made it impossible for a normal user, who only opens cases when they need to change batteries.  If you're the guy holding the soldering iron, anything's possible.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snoof on February 02, 2008, 04:54:20 PM
you could also parallel a cap (.68 - 25uf) with R3 and use a switch to cut it in/out for more gain.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 02, 2008, 05:10:19 PM
To anyone who's built this circuit -- stick a boost in front!

I added a mosfet boost circuit before the start of the tube boost and the result is a much more pleasing breakup than the gain pot provides. It also seems to make the tube boost more humbucker friendly. Cranking both the boost and the gain gives a fat saturated tone that I totally dig. Adding the boost was enough for me to decide that this circuit deserves an enclosure and a spot on my pedalboard  ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on February 02, 2008, 11:17:59 PM
To anyone who's built this circuit -- stick a boost in front!

I added a mosfet boost circuit before the start of the tube boost and the result is a much more pleasing breakup than the gain pot provides. It also seems to make the tube boost more humbucker friendly. Cranking both the boost and the gain gives a fat saturated tone that I totally dig. Adding the boost was enough for me to decide that this circuit deserves an enclosure and a spot on my pedalboard  ;D

Out of curiosity what boost did you use?  Maybe a sound sample if you have time?

Thanks!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 02, 2008, 11:42:42 PM
The boost I used is a SHO, because I had one in my pile of circuits and the only other boost I had floating around was an EH LPB that I don't like.

I'll look into a sample; unfortunately I'm having some massive issues with pro tools and OS X and pretty much can't use pro tools at all at the moment. ARRRGH.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on February 03, 2008, 12:54:39 AM
Cool Andrew_K!  Are you planning to box the booster in the same chassis and have a separate switch for the boost ckt?

Sorry to hear about your recording setup woes... hope you get it fixed soon!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on February 03, 2008, 01:45:08 AM
Hi
Any booster with about 10dB of gain will be fine.  The Stratoblaster booster, which gives pleasant boost of up to about 15dB, is nice.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 03, 2008, 02:25:51 AM
Are you planning to box the booster in the same chassis and have a separate switch for the boost ckt?

Same box, but no separate switch. It'll just be a pre-gain control or similar. With the tube laying flat between the 3PDT and the pots, it all fits nicely in a hammond BB.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 05, 2008, 06:23:25 PM
Hey, I noticed that in the layout it wasn't stated that C3 is electrolytic, as far as I remember it is an electrolytic in the schematic..Should it be a big trouble to put an unpolarized cap or it has to be polarized???  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mojo_hand on February 05, 2008, 06:39:58 PM
Unpolarized is fine.

I don't think you'll find many situations where a polarized cap is required.  They're cheaper, and that can matter, but unpolarized will usually work in their place.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 05, 2008, 08:12:34 PM
'k, thx!!!  ;)
Title: BUILD REPORT
Post by: Renegadrian on February 13, 2008, 09:12:58 PM
All right, I used a non polarized then...
I built it today...It was a little more difficult than I believed...A lot of wiring and my wiring isn't the best, maybe I am ok in on board wiring but there is NO board here, so... ;D
Anyway, I enjoyed my rendition, but I believe I went something wrong, maybe...It sounds quite good, it gives a nice bluesy sound but a little less distorsion compared to the video I saw on youtube...When it's engaged, there is a bloody background noise...Also, the LED doesn't light...Maybe I swapped the wires (LED-ground?)
I'll post some pics tomorrow...

EDIT: The valve lights up very little...It's an EH 12AU7
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on February 13, 2008, 09:36:21 PM
Wild guess: earthing problem. 
Try gounding everything to 1 point (easily said, sometimes difficult to do)
Title: Re: BUILD REPORT
Post by: ambulancevoice on February 14, 2008, 02:41:06 AM

EDIT: The valve lights up very little...It's an EH 12AU7

well, tubes arnt light bulbs
Title: BUILD REPORT
Post by: Renegadrian on February 14, 2008, 06:56:26 AM
brett, I used the layout that I saw on the second page of this thread.
http://img292.imageshack.us/img292/1110/tubepedalpm0.jpg

Both IN and OUT sleeve have  4 ground wires connected...and one is the connection between them.
Any other clue? What about the LED??? I found that if I put the power plug just at the very beginning, the circuit still works and the LED lights...
Title: VERO exercise
Post by: Renegadrian on February 14, 2008, 09:06:17 AM
I tried to put everything on vero, as suggested in the first pages...I should add the LED part...
Anyway, check if it's correct or there are errors in it...

(http://img101.imageshack.us/img101/3442/valvecasterdg2.th.jpg) (http://img101.imageshack.us/my.php?image=valvecasterdg2.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 15, 2008, 10:26:12 AM
I solved the LED thing, it wasn't made to be soldered to the free lug, but together with the positive...
I made a gallery for your curiosity...

http://web.tiscali.it/renegadrian/

I used a TEKO case, which has enough room for the valve and all the pieces...I built a "wall" for the tube with wood...I triple checked its measures and cut it to totally fit in - I was going to glue it, but it's not necessary. I made two holes, one that contains the tube socket (then glued in) and another one for the wires. I also made two "peepshow" holes in the enclosure just above the tube...
I just need to fix the paint inperfections, put some labels on and clear coat...But well, that's it...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snoof on February 15, 2008, 10:54:58 AM
Looks good  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Sweetalk on February 15, 2008, 11:30:15 AM
Can this be biased to use an 12AX7?, with more gain obviously... It's a very nice build!, I have to try it but I have only 12AX7's handy...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 15, 2008, 12:49:07 PM
i have a spare 12ax7 laying around, I tried it but the result is not the best...As you haven't got a good voltage that this valve needs, it sounds "boomy" and you can feel it's not the right choice...While the 12AU7 is good enough and can sound sweet with 9-12V

You may want to try Marsha Valve Tube, it uses a 12AX7 and it should be easy as this one, also it seems it's verified.
SCHEM (http://www.aronnelson.com/gallery/v/vanhansen/marshavalve_tube_02.gif.html) and VERO LAYOUT (http://www.aronnelson.com/gallery/v/Mihkels-layouts/MarshaValveTube.jpg.html?g2_imageViewsIndex=1)

This is my next one, i already have valve socket enclosure, so I just need some little pieces...AndI'm gonna try the same building process, with the same valve placement. (altough I regret that this 12AU7 doesn't light that much...)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 15, 2008, 04:55:59 PM
Be sure to tell us how it sounds once you're done.  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 15, 2008, 06:12:02 PM
Sure I'll do, I think I fell in love with valves...(after all, I built this Valvecaster on Valentine's...)
I ordered the bits I miss...Next week Marsha will be mine!!! (the circuit, not a woman...)  :icon_lol:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 15, 2008, 08:43:32 PM
Improved vero version of the Valvecaster...It should work, I optimized and completed the layout...
(http://img182.imageshack.us/img182/7794/valvecasterv02sj6.th.jpg) (http://img182.imageshack.us/my.php?image=valvecasterv02sj6.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 16, 2008, 12:53:03 PM
That's nice.
If you want the tone pot to work the "normal" way (bass-left, treble-right) you should move C3 to lug 1.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripdivot on February 17, 2008, 05:58:02 PM
I just built a Valvecaster driving an SHO. I have installed a 100K master volume pot in place of the 100K resistor on the output of the SHO. It is currently on the bread board but will soon be on the pedal board. I love the way the Valvecaster overdrives the SHO mosfet. I tried the SHO in front of the Valvecaster as well but I like it better the other way. If you crank up the gain on the SHO as well as the gain and level control on the VC there is plenty of gain to be had. All this is running on 9 volts. I am bypassing the Valvecaster gain pot with a 2.2nf cap. This helps maintain some brightness when the VC gain is turned down. For the input cap on the Valvecaster I am using a combination of caps to give me 2.7nf. This helps tighten up the bottom end. The tube is a nos 12au7. I have been playing with the cap values in this circuit for a week and it sounds awesome with my Strat now into my blackface Fender amp. Seems like there are endless tones to be had with this pedal. It cleans up well with the guitar volume as well.
Title: Vero v0.4
Post by: Renegadrian on February 17, 2008, 08:40:26 PM
Here's version 0.4 - removed unnecessary strips and optimized it again, tone now working the right way.
Should work...
Next is the MVT redrawn by me, it displays better in this layout...Credit obviously to the makers of the previous schem and layout...

(http://img183.imageshack.us/img183/9308/valvecasterv04yu8.th.jpg) (http://img183.imageshack.us/my.php?image=valvecasterv04yu8.jpg)(http://img301.imageshack.us/img301/3672/marshavalvetubeop6.th.jpg) (http://img301.imageshack.us/my.php?image=marshavalvetubeop6.jpg)


BTW, sorry for my ignorance...what is a SHO?!  ???

Also, I know that there's ORMAN Tube Driver that's working on 9-12V, I found some good layout I'd be posting here...
Title: Re: Vero v0.4
Post by: kurtlives on February 17, 2008, 09:32:57 PM
Here's version 0.4 - removed unnecessary strips and optimized it again, tone now working the right way.
Should work...
Next is the MVT redrawn by me, it displays better in this layout...Credit obviously to the makers of the previous schem and layout...

(http://img183.imageshack.us/img183/9308/valvecasterv04yu8.th.jpg) (http://img183.imageshack.us/my.php?image=valvecasterv04yu8.jpg)(http://img301.imageshack.us/img301/3672/marshavalvetubeop6.th.jpg) (http://img301.imageshack.us/my.php?image=marshavalvetubeop6.jpg)


BTW, sorry for my ignorance...what is a SHO?!  ???

Also, I know that there's ORMAN Tube Driver that's working on 9-12V, I found some good layout I'd be posting here...
Nice layout there...What is the second layout you posted.

SHO Super Hard On....made by Zvex
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 17, 2008, 09:43:48 PM
Chris, the second layout is based on the  Marsha Valve Tube
SCHEM (http://www.aronnelson.com/gallery/v/vanhansen/marshavalve_tube_02.gif.html) and VERO LAYOUT (http://www.aronnelson.com/gallery/v/Mihkels-layouts/MarshaValveTube.jpg.html?g2_imageViewsIndex=1)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on February 17, 2008, 09:50:43 PM
O very nice...

How is it?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 18, 2008, 07:28:43 AM
Have to build it yet, got the parts on the way - I'll report it in some days...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 18, 2008, 06:30:22 PM
Renegadrian: nice work on the vero layout; I might have to give that a try for my second build. Looks much easier to integrate with a boost circuit. My current favorite setup for this circuit is a medium gain jfet boost before and another after. The first one heats up the signal a little for the tube and the second one gets slammed by the tube boost. I also like a mosfet boost before the tube boost, but I haven't tried one after yet.

I was having a problem with mine whereby it would cut in and out, with an audible pop as it was cutting out. The solution for me has been running it at 12v.
I ran it for over an hour last night at 12v with no problem, where as at 9v it starts popping and dying within 2 minutes. It might just be the tubes, but I tried a couple of different ones and the result was the same.
Title: vero
Post by: Renegadrian on February 18, 2008, 07:49:09 PM
Andrew thank you for your kind words, I'm just a noob and I found it a good exercise to do, now I know a little more...
I will build another one, gotta try the inside fet boost!!!  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripdivot on February 18, 2008, 08:01:00 PM
I have had mine running on 9 volts for at least 20 hours with several different 12au7's. So far I have had no problems. The tubes are all NOS though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 18, 2008, 09:23:43 PM
I have had mine running on 9 volts for at least 20 hours with several different 12au7's. So far I have had no problems. The tubes are all NOS though.

Yeah, it's probbly the tubes I'm using -- what do you expect for $1 for two off fleaBay ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 19, 2008, 02:15:21 AM
Just built the vero version, still gotta tweak it a bit, but noticed two minor mistakes in it. C3 should be 1uF instead of 1nF, and you forgot to mention that pin 4 should be grounded. It's pretty obvious when looking at the schematics but still..
Title: Vero v0.5
Post by: Renegadrian on February 19, 2008, 11:35:40 AM
Aren, thx for pointing out those errors, so here is version 0.5!!! (should be final...)

(http://img155.imageshack.us/img155/3599/valvecasterv05qs5.th.jpg) (http://img155.imageshack.us/my.php?image=valvecasterv05qs5.jpg)


Hey, post some pics of your version!!! I'll be glad to see them!!!
Title: TWINCASTER
Post by: Renegadrian on February 19, 2008, 02:49:41 PM
Based on the Twincaster schem, seen some pages ago and developed by Dano (again) I'd like to show you my Twincaster VERO version...
Here is my vero (should be correct, but hey...)

(http://img220.imageshack.us/img220/460/twincasterv01yq0.th.jpg) (http://img220.imageshack.us/my.php?image=twincasterv01yq0.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 19, 2008, 04:37:24 PM
Will do, as soon as I get it up and running. Right now it doesn't work at all, seems like bad contacts somewhere, but I can't seem to locate the source of the problem...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 19, 2008, 05:35:36 PM
Since every time i report a non-working build in this forum I figure it out in ten minutes, I'll try this method again... :)

All I get is some ground hum (which is strange, since it is pretty much star-grounded) but no real signal. Any idea what can be wrong there?
I messed with the connections, and it moved between no sound it all, only ground hum, hum+signal and clean signal. After a while it settled on "hum alone" and I can't seem to find the source of the problem...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 19, 2008, 05:45:11 PM
Well, it can be a 100's problems...Grounding-some connection you just forgot-bad valve-really bad DC adapter...Dunno... ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 19, 2008, 05:50:52 PM
Well, as expected, it started working 10 seconds after posting  ;D
There is still a ground hum, but that I can fix...

If I only knew what I did to get it working...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 19, 2008, 06:04:10 PM
I just build version 5 and it works!

 Wired direct without a switch, but will add soon. Great layout. I did revert back to the earlier version that had the 8 pin lineup on the board. I just corrected the parts layout. Thanks for putting the layout together.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 19, 2008, 06:32:36 PM
Oh man, that's great!!! What if I tell you it's my first vero layout I design?!?! I am so happy it worked!!! Time for another beer then!!!  :icon_wink:

I just fell in love with those valve projects...I will be buiding marsha, then Orman tube driver and I'll try the Twincaster (valvecaster with 2 valves)

Did you put your creation in some enclosure!? Pics are welcome, as for Aren!!!



PS a big thank you goes to Dano, he started it all...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 19, 2008, 08:12:03 PM
Just wired up the switch and everything works great. I don't have a 100k pot for the gain as I didn't have any 50k. I want to see if I can tame the gain a bit. Its capable of some decent amounts of gain. I am a couple weeks away from creating an enclosure. I want to come up with something good for my first tube build

Echo your sentiments, Thanks to all on the thread.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 19, 2008, 08:33:30 PM
It's still VERY unstable (I'm beginning to think the volume pot should be replaced), but here's the pic:
http://picasaweb.google.com/lh/photo/gSqPT9t6cpgypPkAKZsVdg (http://picasaweb.google.com/lh/photo/gSqPT9t6cpgypPkAKZsVdg)

It's my first attempt to use the "dark t-shirt transfer paper" (with the aid of my beautiful talented wife  ;)).
The actual box was painted with regular acrylic paint and finished with water-based clear coat.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 20, 2008, 01:16:11 AM
This is getting weird.
I replaced the pot, and it did improve the stability issues. Worked great, only had this annoying buzz in the background. Since I eliminated the possibility of a ground loop, I decided I would try and stabilize the power supply by adding a 180ohm resistor in series with the DC jack. It stopped working altogether, so I measured the power at the DC node. It was 2.53V!  :o Once I disconnected the resistor from the vero, and measured it with no load, I got 15.3V, so the resistor is fine.
Any thoughts?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 20, 2008, 01:00:49 PM
"Just wired up the switch and everything works great. I don't have a 100k pot for the gain as I didn't have any 50k. I want to see if I can tame the gain a bit. Its capable of some decent amounts of gain. I am a couple weeks away from creating an enclosure. I want to come up with something good for my first tube build"


To tame the gain I would lower R2 and R3. 220k and 100k seem pretty high for a low voltage circuit. Even in a regular high voltage amp the normal value is just 100k. So maybe cut them in half.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snoof on February 20, 2008, 01:26:44 PM
if you bring down that 220k to 100k it will def lower the gain a bit.  I built mine with both plate r's at 100k.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 20, 2008, 01:48:41 PM
Thanks for the replies. I may try and add a toggle switch to have the higher gain setting available. I will give that a shot and report back
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 20, 2008, 06:09:40 PM
I want to see if I can tame the gain a bit.

hehe, I did the complete opposite. A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 20, 2008, 06:16:40 PM
Going from 50K to 1M...Hell, now that's a big difference!!! So it gains more gain?!  :icon_mrgreen:
And for what I understood...higher resistance value = more gain?
gotta try this pot change...what about 100K or 500K???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 20, 2008, 06:28:04 PM
Just built my 3rd valvecaster. My first one was for me, and the first time I brought it to a rehearsal, my buddy asked me for one. I made him one, and his brother wanted one  :P.His brother actually offered to pay for it!

Long story short, these things rock!


Quite a thread we got going here aswell. I looked back to my first posts on this thread way back, and I realized this thread is what prompted me into building tube amps. 2 amps and 3 Valvecasters later, I finally feel like I know a thing (maybe 2) about tubes.

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 20, 2008, 06:32:38 PM
Oh, and by the way, I had my friend bring his to a rehearsal, and afterwards, we got it set up with a switch that cuts all the gain directly to clean boost. I brought my meter, and about 50 resistors valued 1ohm to about 15k. We figured out where the maximum clean headroom with his main axe on full volume was, I measured it, and ended up putting in a 12k resistor, and added a stomp switch for clean boost (did I mention I brought my drill aswell  ;D).

 Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on February 20, 2008, 07:09:38 PM
And for what I understood...higher resistance value = more gain?
It would seem that's the case. I'm a newbie too, so I just mess with things until I break it or it sounds cool  :D

I'm a little concerned about the affect an increased gain would have on tube life. Maybe one of the more experienced guys can chime in here...?

After experimenting with all sorts of boosts before and after, I'm going to box mine up without any extra gain stages (maybe a high impedance buffer at input to retain more sparkle, I'll be testing that on the weekend). If I want more gain I'll just use another boost or OD pedal before or after the tube drive.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 20, 2008, 07:23:48 PM
I'll give about 90% confidence on this one...so don't be mad if im wrong  ;D

I don't believe the added gain will do anything to tube life, at least on a measureable scale. Keep in mind, these things are designed to run more than 10-20 times as much voltage as you are running here. If theres anything that is going to reduce tube life here, it is the fact that you are running them on suck low voltage, which (I believe) causes stripping, and decreases life.

So, unless anyone corrects me otherwise, go ahead. Build a gain monster!

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 20, 2008, 07:47:36 PM
I added a 7812 regulator, and it now works like a charm!
Makes my acoustic sound half decent when going direct!  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on February 20, 2008, 07:50:07 PM
Oh, and by the way, I had my friend bring his to a rehearsal, and afterwards, we got it set up with a switch that cuts all the gain directly to clean boost. I brought my meter, and about 50 resistors valued 1ohm to about 15k. We figured out where the maximum clean headroom with his main axe on full volume was, I measured it, and ended up putting in a 12k resistor, and added a stomp switch for clean boost (did I mention I brought my drill aswell  ;D).

 Zach
How did you wire it?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snoof on February 21, 2008, 11:38:31 AM
running the heaters at above or below the required voltage will do harm to the tube over time.  I wouldn't use any of your NOS super mojo tubes in this design unless you run the heaters at 12v.(or 6v if using pins 4+5 and 9).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 21, 2008, 12:40:11 PM
Oh, and by the way, I had my friend bring his to a rehearsal, and afterwards, we got it set up with a switch that cuts all the gain directly to clean boost. I brought my meter, and about 50 resistors valued 1ohm to about 15k. We figured out where the maximum clean headroom with his main axe on full volume was, I measured it, and ended up putting in a 12k resistor, and added a stomp switch for clean boost (did I mention I brought my drill aswell  ;D).

 Zach
How did you wire it?

Sorry if this is wrong, I'll go look at the schem in a minute...

but I just used a spdt, pin 3 of 12au7 going to middle lug of switch, one side of switch had pot, the other had the 12k

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 21, 2008, 02:25:36 PM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 21, 2008, 02:31:13 PM
Hmmm...

I didn't have the schematic with me, all I know is I used a spdt somehow and a 12k resistor.

Maybe it was "after the pot" to the middle lug, one side going to ground and the other to a 12k to ground.



Zach

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 21, 2008, 03:39:05 PM
For the benefit of Mr. Chawk (and anyone else who wants to build this thing), here are some gut shots of the point to point version of the Valvecaster. Please note that this was done quickly and eagerly, so the soldering is rather crappy.  :icon_wink:

(http://i47.photobucket.com/albums/f191/krinor/Valvecastergut4.jpg)

(http://i47.photobucket.com/albums/f191/krinor/Valvecastergut3.jpg)

(http://i47.photobucket.com/albums/f191/krinor/Valvecastergut2.jpg)

(http://i47.photobucket.com/albums/f191/krinor/Valvecastergut1.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 21, 2008, 04:03:50 PM
NICE SHOTZ!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on February 21, 2008, 04:17:15 PM
Fantastic!!! Much thanks!   :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Boogdish on February 21, 2008, 05:33:58 PM
so the soldering is rather crappy.  :icon_wink:

if that's what counts as crappy, then I got a LOTTA catching up to do.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DryRoasted on February 21, 2008, 05:37:52 PM
I knocked this up today to have a play with the circuit.  Looking around the net I found a few tube circuits in the same vien and this board is enitirely plug and play to allow maximum tweekage.  Me and her are gonna get real aquanted over the next few weeks :)  (sorry, hill billy mode)

(http://www.dryroasted.f2s.com/vc1.jpg)

<edit> Yes I know it shpuld be a glass of JD and coke for the full rock n roll kudos but hey, i'm English :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 21, 2008, 06:05:00 PM
Now that's nice and clean!
Be sure to post your findings here (once you get to know her).
And I thought englishmen only drank tea ?  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 21, 2008, 06:38:55 PM
Well, There's the Ruby Tuby (http://www.sophtamps.ca/schematics/ruby_tuby_1.jpeg), both preamp or full amp - and other sophtamps creations...Sad I suck at reading schematics...
If I only find vero/perf/pcb of any of these...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 21, 2008, 09:22:41 PM
Hmmpf... I would just replace the opamp stage with a JFET buffer, stick the Valvecaster in front of it, and feed it to a 386 amp.
Seems easier...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 02:24:08 AM
Well, There's the Ruby Tuby (http://www.sophtamps.ca/schematics/ruby_tuby_1.jpeg), both preamp or full amp - and other sophtamps creations...Sad I suck at reading schematics...
If I only find vero/perf/pcb of any of these...

Surely you are aware of Dano's "Tube Cricket" ? That one seems like a logic progression from the Valvecaster.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DryRoasted on February 22, 2008, 09:21:54 AM
First observations from the valvecaster test rig:

Using a 12AX7 at 12V and no tone stack, everything else stock - a bit "wooly" for my liking not alot of note defination, a bit boomy (this is coming from a confirmed metal head).  Change the input cap (C1) to 22nF and its a whole new game.  Lots of ACDC-esque tone, lovely response and works well with humbuckers (no idea about single coil).

Next up, same as above but changed R3 from 100K to 240K and moved VR1 from the leg of tube pin 3 to pin 8 and jumpered pin three to ground - Not a masive change but enough to give a noticable comparison.  Most obvious thing is the response of the gain control VR1, before, most of the control was in the last 1/4 turn but now its more evenly spread.  Overall tone remains useable.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 22, 2008, 10:07:07 AM
Cleaning up the tube boost - these were quotes from this thread

"To tame the gain I would lower R2 and R3. 220k and 100k seem pretty high for a low voltage circuit. Even in a regular high voltage amp the normal value is just 100k. So maybe cut them in half."

"if you bring down that 220k to 100k it will def lower the gain a bit.  I built mine with both plate r's at 100k. "
 
"but I just used a spdt, pin 3 of 12au7 going to middle lug of switch, one side of switch had pot, the other had the 12k"


I am going to get the iron ready today to try some of these. I was planning on putting a dpdt switch in for R2 to go between 220K and 100K based on the recomendations above. Then I saw the idea to put a spdt switch between the gain pot and pin three. I am starting to follow where lowering the resistance will cause the pedal to be a bit more clean. Given the two options, which one will provide a cleaner setting? I like the idea of being able to toggle between a cleaner sound and an overdrive sound.  I am not so clear on the different roles of each pin of the tube so I don't know if changing the value going to pin 3 vs pin 5 will do this. 

Thanks to all for the suggestions
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 10:29:35 AM
Okay, here's another little mod for the Valvecaster:

A usefull tonal variation can be achieved by implementing a switchable negative feedback.

Put a 22k resistor and a spdt switch between the output and the cathode of the second stage (lug 8 ).
You can also make a "bass boost" filter out of it by inserting a capacitor between there as well.
I currently have a 0.056uF cap in series with the resistor. This removes some of the mid range and helps keep things a little bit more together. It sounds nice and clean at low gain settings and it also sounds pretty good with everything maxed. More defined puch in the bottom and not so shrill. I've tried this with larger caps as well but it tends to get a bit too boomy.
All in all this is a nice little mod which will tame the gain a bit. Nothing dramatic, but it helps if you want to tune the thing for a more clean boost.

Here's an illustration:

(http://i47.photobucket.com/albums/f191/krinor/Valvecastergut1highpass.jpg)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on February 22, 2008, 11:59:28 AM
Any preferences in brand name of AU7 tube used?

Examples:
Electro-Harmonix
EH Gold
Mullard
Sovtek
Tesla
Sino-China
Odd Ball
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 12:02:58 PM
Personally I don't use EH anymore after discovering how much better almost anything else sounds.  :icon_twisted:
I currently use a brand called Tube Amp Doctor. They sound very transparent and are a bit on the treble side of the scale.
Tung Sol and JJ would be excellent choices.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 22, 2008, 03:38:02 PM
I gave that a shot. It cleaned up it pretty good. I am going to play around with that for a bit before trying any of the other gain reducers. I like the bass increase by switch, but may change the value to reduce the bass a bit

Thanks

Okay, here's another little mod for the Valvecaster:

A usefull tonal variation can be achieved by implementing a switchable negative feedback.

Put a 22k resistor and a spdt switch between the output and the cathode of the second stage (lug 8 ).
You can also make a "bass boost" filter out of it by inserting a capacitor between there as well.
I currently have a 0.056uF cap in series with the resistor. This removes some of the mid range and helps keep things a little bit more together. It sounds nice and clean at low gain settings and it also sounds pretty good with everything maxed. More defined puch in the bottom and not so shrill. I've tried this with larger caps as well but it tends to get a bit too boomy.
All in all this is a nice little mod which will tame the gain a bit. Nothing dramatic, but it helps if you want to tune the thing for a more clean boost.


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 03:48:59 PM
I gave that a shot. It cleaned up it pretty good. I am going to play around with that for a bit before trying any of the other gain reducers. I like the bass increase by switch, but may change the value to reduce the bass a bit

Thanks

You can probably go down to 0.033uF and still keep some of the bass boost effect. Or leave the capacitor out and use only the resistor as an ordinary feedback loop. You may also like other resistor values. I tried 10k too but ended up using 22k. Seems like tubes can take a real beating no matter what you throw at them. And what we are dealing with here is just some gentle cuddling anyway.  :icon_wink:

Could someone tell me how it would affect the biasing of the second stage if I put in a 1,5k resistor to ground on the cathode (lug 8 ) ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on February 22, 2008, 03:54:22 PM
By the way - I'm not sure how many of you are into recording, but I just tried this circuit as a mixing tool, and it works fantastic.
I ran a bass track through it, and while it didn't sound that great on its own, when combined with the original clean signal it sounded great. Same deal on vocals that were too thin for my taste.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 04:00:09 PM
By the way - I'm not sure how many of you are into recording, but I just tried this circuit as a mixing tool, and it works fantastic.
I ran a bass track through it, and while it didn't sound that great on its own, when combined with the original clean signal it sounded great. Same deal on vocals that were too thin for my taste.

Done that yes. I use it for all kinds of things. Works good with vocals. Nice to enhance things with, especially with some gain reduction as mentioned above.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on February 22, 2008, 04:47:57 PM
I might try leaving the cap and using the switch to just add a bit more bass, might even keep the current value. After playing with it a bit more, I think I might trying cleaning up the gain with a second footwitch with the resitor on pin 3 and see how that sounds. I think it would be nice to have the versatility to kick the gain on when needed.  This has been a good circuit to experiment on.


Thanks 



[/quote]

You can probably go down to 0.033uF and still keep some of the bass boost effect. Or leave the capacitor out and use only the resistor as an ordinary feedback loop. You may also like other resistor values. I tried 10k too but ended up using 22k. Seems like tubes can take a real beating no matter what you throw at them. And what we are dealing with here is just some gentle cuddling anyway.  :icon_wink:

Could someone tell me how it would affect the biasing of the second stage if I put in a 1,5k resistor to ground on the cathode (lug 8 ) ?
[/quote]
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 22, 2008, 05:30:11 PM
Without the capacitor it will just be an ordinary global negative feedback as seen in many old class A amps (Fender champs etc). Leaving it out will just flatten things out a little. But that's probably what yo were after anyway.
How about putting a 50k pot in there instead and tweaking it until you find the optimal setting ? (And then measure the resistance and report back to us of course  :icon_wink: )
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 22, 2008, 07:39:39 PM
Any preferences in brand name of AU7 tube used?

Examples:
Electro-Harmonix
...

Well, I have an EH in and my Valvy doesn't sound as expected, I know everyrthing's ok so I am surely going to try another brand to make it sound better, maybe jj or anything I could find on evilBay...For this little esperience of mine, EH are a no-no, also I read bad comments elsewhere on the forum, so...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on February 22, 2008, 08:00:57 PM
[opinion/]

Those comments you read are correct, in my mind.

I've got 2 EH 12au7, and they sound sterile, crappy, plain old bad. In fact every EH tube I have tried sounds like this, unfortunately.

I've still got some baldwin's, and just got a bunch of conn's, and they both sound WAY better. I believe they are RCA made, judging by looks?

[/opinion]

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on February 23, 2008, 07:25:57 AM
For an excellent range of tubes try these guys:

http://www.tubedepot.com/index.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: LMJS on February 23, 2008, 02:24:37 PM
Tube Depot are great!  No "hidden" fees for orders, you get what you pay for with no additional charges other than the usual shipping.
I can think of at least one tube store that could learn from them.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 23, 2008, 07:34:28 PM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.

As I am on the "MORE GAIN" party, I think I'll do a vero version socketing the above mentioned R1 and R2 trying some increased values, also swapping some gain pots, like 100k, 250k, 500k...
It should "gain" some gain that way, am I right?!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 25, 2008, 12:47:21 PM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.

As I am on the "MORE GAIN" party, I think I'll do a vero version socketing the above mentioned R1 and R2 trying some increased values, also swapping some gain pots, like 100k, 250k, 500k...
It should "gain" some gain that way, am I right?!

Yup. The ultimate tweaker box would probably be to replace the plate resistors with 250k pots. Then put a 1k resistor on the collectors to ground. Bypass each collector resistor with a 5uf capacitor. Put the 50k "gain" pot in series with the bypass capacitor. And dial it in!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 27, 2008, 05:25:03 PM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.

As I am on the "MORE GAIN" party, I think I'll do a vero version socketing the above mentioned R1 and R2 trying some increased values, also swapping some gain pots, like 100k, 250k, 500k...
It should "gain" some gain that way, am I right?!

Yup. The ultimate tweaker box would probably be to replace the plate resistors with 250k pots. Then put a 1k resistor on the collectors to ground. Bypass each collector resistor with a 5uf capacitor. Put the 50k "gain" pot in series with the bypass capacitor. And dial it in!

Let me revise that slightly:

Replace the plate resistors with 250k pots. Then put a 10k resistor on the collectors to ground. Bypass each collector resistor with a 1uf capacitor. Put a 5k "gain" pot in series with the bypass capacitor. And dial it in!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: earthtonesaudio on February 27, 2008, 06:19:51 PM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.

As I am on the "MORE GAIN" party, I think I'll do a vero version socketing the above mentioned R1 and R2 trying some increased values, also swapping some gain pots, like 100k, 250k, 500k...
It should "gain" some gain that way, am I right?!

Yup. The ultimate tweaker box would probably be to replace the plate resistors with 250k pots. Then put a 1k resistor on the collectors to ground. Bypass each collector resistor with a 5uf capacitor. Put the 50k "gain" pot in series with the bypass capacitor. And dial it in!

Let me revise that slightly:

Replace the plate resistors with 250k pots. Then put a 10k resistor on the collectors to ground. Bypass each collector resistor with a 1uf capacitor. Put a 5k "gain" pot in series with the bypass capacitor. And dial it in!


When you say "collector," you're really talking about "cathode," right?  (or kathode if you prefer)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 28, 2008, 10:35:30 AM
First observations from the valvecaster test rig:

Using a 12AX7 at 12V and no tone stack, everything else stock - a bit "wooly" for my liking not alot of note defination, a bit boomy (this is coming from a confirmed metal head).  Change the input cap (C1) to 22nF and its a whole new game.  Lots of ACDC-esque tone, lovely response and works well with humbuckers (no idea about single coil).


So you say it works well with a 12AX7 too? Did you try to increase R1 and R2 values, as well as the GAIN pot value???
We already said it is "gainier" with increased values of the above...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on February 28, 2008, 11:54:40 AM
Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.

As I am on the "MORE GAIN" party, I think I'll do a vero version socketing the above mentioned R1 and R2 trying some increased values, also swapping some gain pots, like 100k, 250k, 500k...
It should "gain" some gain that way, am I right?!

Yup. The ultimate tweaker box would probably be to replace the plate resistors with 250k pots. Then put a 1k resistor on the collectors to ground. Bypass each collector resistor with a 5uf capacitor. Put the 50k "gain" pot in series with the bypass capacitor. And dial it in!

Let me revise that slightly:

Replace the plate resistors with 250k pots. Then put a 10k resistor on the collectors to ground. Bypass each collector resistor with a 1uf capacitor. Put a 5k "gain" pot in series with the bypass capacitor. And dial it in!


When you say "collector," you're really talking about "cathode," right?  (or kathode if you prefer)

Yes. I goofed up my tube with my transistor lingo!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 05:13:47 PM
Some pictures of my latest Valvecaster. This time with true bypass in a small enclosure.
I wired it so that the input jack functions as an on/off switch for the tube (on if jack is inserted). Thus the tube will stay on all the time for imediate action once the effect is engaged.

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterrd1.jpg)

And the interior:

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterinterir.jpg)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 09, 2008, 05:21:06 PM
Man, I just love your pedal!!! Nice and classy!!! Is it the standard version or it has some mods!?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 05:23:28 PM
Standard. I really love it the way it is. But I AM going to build a twin version soon. Just have to sell this one first to get some cash for more tubes.  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 09, 2008, 05:44:55 PM
+1 on the twincaster, I am waiting my tubes to arrive, an angel sent me some for free...And then I'll go twin too!!!
Will post asap the results...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 05:50:09 PM
Please do  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on March 09, 2008, 05:55:16 PM
Some pictures of my latest Valvecaster. This time with true bypass in a small enclosure.
I wired it so that the input jack functions as an on/off switch for the tube (on if jack is inserted). Thus the tube will stay on all the time for imediate action once the effect is engaged.

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterrd1.jpg)

And the interior:

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterinterir.jpg)



That is a great piece of work, inside and out. I'm a sucker for chrome/polished metal :)

Good job!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 06:02:37 PM
Thanks Dano!
Actually (admittedly) much of my work is inspired by all the cool stuff on your amazing website!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 09, 2008, 06:03:28 PM
+1
thanks to you for your circuit, we enjoyed it so much, as you can see...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on March 09, 2008, 06:07:32 PM
Thanks Dano!
Actually (admittedly) much of my work is inspired by all the cool stuff on your amazing website!  :icon_wink:


My pleasure. Wait until you see the latest project.  :icon_twisted: :icon_twisted: :icon_twisted:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 06:14:42 PM
Thanks Dano!
Actually (admittedly) much of my work is inspired by all the cool stuff on your amazing website!  :icon_wink:


My pleasure. Wait until you see the latest project.  :icon_twisted: :icon_twisted: :icon_twisted:

Oh crap! What have you been up to now ?!  :icon_lol:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on March 09, 2008, 06:34:10 PM
Thanks Dano!
Actually (admittedly) much of my work is inspired by all the cool stuff on your amazing website!  :icon_wink:


My pleasure. Wait until you see the latest project.  :icon_twisted: :icon_twisted: :icon_twisted:

Oh crap! What have you been up to now ?!  :icon_lol:


Microprocessor-controlled LFO/sequencer. Finished the basic coding tonight. Now its on to polishing and debugging.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 09, 2008, 06:41:38 PM
Now THAT is beyond that piece of grey fat which I laughingly call my brain.  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripdivot on March 10, 2008, 01:28:04 AM
Here is the schematic for my latest dual 12AU7 circuit. It is currently still on the bread board and I think it sounds great. It is designed to run on 9 volts. It goes from clean boost all the way up to "brown" type gain. It cleans up nice with the guitar volume as well.

(http://img80.imageshack.us/img80/8932/lvlrev3bmprk9.th.png) (http://img80.imageshack.us/my.php?image=lvlrev3bmprk9.png)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on March 10, 2008, 05:10:19 PM

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterrd1.jpg)

And the interior:

(http://i47.photobucket.com/albums/f191/krinor/Valvecasterinterir.jpg)



Kristian,

That pedal is tight! You've got some of the slickest looking boxes. Post some sound clips of this beauty... I just picked up some 12AU7s and was thinking of building it.

Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 10, 2008, 05:36:50 PM
Thanks Matt.  :icon_cool:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cheeb on March 10, 2008, 08:37:41 PM
I built this today with a 12au7. I would post pictures, but it looks identical to Kristian's. (Sorry, I liked the look and the layout)

I like it. It's definitely vintage-y. It drives a solid state smoothly, and it makes my Fender Bronco (Vibro-champ) sounds downright nasty.

One thing, though, do any of you guys have that scratch on your gain pot that sounds like DC?

--Cory
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 10, 2008, 09:12:53 PM
Following my layout below, how do I get rid of the tone control? Shall I have to leave out only C4 or both C3 and C4?
Also, do you think that the tone control below  I found at Dano site would work better???
(http://beavisaudio.com/Projects/BigMuffToneControl/BodyOnPot.gif)(http://img361.imageshack.us/img361/3889/valvecasterv05sv9.th.jpg) (http://img361.imageshack.us/my.php?image=valvecasterv05sv9.jpg)


Also,  I'd really love to see the schematics of those shiny boxes...Look at specs...Guess what kind of tube they use^!?
http://www.voxamps.co.uk/pedals/cooltron.asp
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on March 11, 2008, 02:06:19 AM
Hi
that tone control may need a buffer before it, and (especially) a buffer after it.  JFET buffers are simple and effective (4 parts!)
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 11, 2008, 03:44:06 AM
Just finished my Matsumin Tsunami Tube Overdrive!  :D

The middle knob is just covering a hole I drilled for a different tone stack that didn't work.  This is actually my 2nd revision back to the original schematic.  Sounds great!

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/MatsuminTubeOD.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 11, 2008, 03:55:10 AM
Looking good!
Cool idea to put that japanese painting on it.
I'm thinking that maybe you could use that extra pot for some sort of sweepable feedback loop filter thingy ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 11, 2008, 04:14:28 AM
Thanks Krinor!
Great suggestion for the middle knob.  That graphic actually came out that way by accident.  Originally it was supposed to be color.  The gory details are on the "Pictures!" thread.   :D

This was just a prototype so you'll also notice an extra hole on the side.   :icon_rolleyes:

The next one will be much cleaner (I hope) :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 11, 2008, 04:50:53 AM
Put a switch in the extra hole to turn the sweepable filter on or off !   :icon_mrgreen:
Then sell it on ebay for loads of $$  :icon_twisted:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cuberius on March 11, 2008, 06:16:28 AM
Is there any way to mod the Valvecaster so it sounds good with an active bass guitar?
I'd love to build this stuff, but I would also like to use it.  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 11, 2008, 08:40:12 AM
Hi
that tone control may need a buffer before it, and (especially) a buffer after it.  JFET buffers are simple and effective (4 parts!)
cheers

Ok - what about my other question - how do I get rid of the tone control? Shall I have to leave out only C4 or both C3 and C4 (and the pot, obviously...)?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 11, 2008, 02:22:04 PM
Looking at the dual tube schematic, the stage between the two tubes, only C4 and VR2 are removed.


here's a rough, unverified splice of the schematic showing two tube stages:

(http://www.beavisaudio.com/Projects/ValveCaster/twincaster.gif)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on March 11, 2008, 04:19:17 PM
C3 stays. That's a DC blocking capacitor. It has nothing to do with the tone control. Just remove C4 and the pot.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 11, 2008, 04:54:53 PM
Its a very basic crude tone control.... And that does not make it bad, so don't read it like that.

I just built one of these....I am thinking if I build another one I will throw in a Fender tone-stack.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 11, 2008, 07:38:24 PM
All right, thx for your explaination...I know it's just a basic tone, it might be a little useful or not...I'd like to try my next one without...

Also,I don't know how it sounds with active bass (don't own one) but sounds quite good with a passive one (maybe a littlle dark for my taste, but it's ok).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cuberius on March 12, 2008, 03:21:51 AM
Also,I don't know how it sounds with active bass (don't own one) but sounds quite good with a passive one (maybe a littlle dark for my taste, but it's ok).

Allright then. That's gonna be my next build. Thanks! :)

p.s. could you record some samples?... TIA  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 12, 2008, 12:42:02 PM
Haven't got the bass at disposal (left it in my drummer's garage) so no samples...


Anyway, here's another 12V tube project...
http://paia.com/manuals/docs/9305-tubehead-manual.pdf
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Salvatore on March 12, 2008, 02:05:55 PM
Haven't got the bass at disposal (left it in my drummer's garage) so no samples...


Anyway, here's another 12V tube project...
http://paia.com/manuals/docs/9305-tubehead-manual.pdf

The voltage from the Tubehead is multiplied to 42 volts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 12, 2008, 03:29:52 PM
Haven't got the bass at disposal (left it in my drummer's garage) so no samples...


Anyway, here's another 12V tube project...
http://paia.com/manuals/docs/9305-tubehead-manual.pdf

The voltage from the Tubehead is multiplied to 42 volts.

Uh, didn't notice, my italian (I guess...) comrade...BTW it gets its power from an usual 12V wall wart...So it's a 12V project!!! :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Salvatore on March 13, 2008, 05:26:22 AM
Ok, :icon_lol:
I heard some positive things about the tubehead and with a few extra components it can be made into a mic pre as well.
At Tapeop there is an article with some mods to upgrade it for better specs.
Beware that the 12V wall wart is AC though, making a + -15V supply a bit like used in the Shaka Tube, an other very interesting low voltage overdrive.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ambulancevoice on March 13, 2008, 06:04:55 AM
i wonder what 3 of these in series would be like????
power 12v and heaters 12v
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 13, 2008, 01:55:37 PM
Okay, since nobody has posted soundclips of this thing yet, I thought I'd give it a shot. Apart from the obvious crappy playing I guess those who wonder how it actually sounds will at least get an idea.  :icon_redface:

http://www.aronnelson.com/gallery/main.php/v/Krinor/Valvecaster+soundclip.mp3.html

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 13, 2008, 02:36:35 PM
Sounds good and bright!  Did you mod it to get it to be more trebbly?  Mine sounds more warm which work really well with rig.

Here's another sound clip buried on page 3 somewhere.
http://www.youtube.com/watch?v=cdcORgmfPl4

I'm hoping to put a sound clip of how my Matsumin sounds with my rig up soon just don't have time to make the recording right now.

Can I upload videos to the gallery or only sound clips?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: culturejam on March 13, 2008, 02:38:42 PM
Very nice, Krinor!

I've got some tube sockets on order, and I'm building this bad boy as soon as they arrive.  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on March 13, 2008, 02:47:08 PM
I found this Tuesday night and built it 24 hours later!!!!! Finished and debugged it last night, but It was too late to really rock out.
I need more gain, tonight Im going to change the plate resistors I think, any sudgested values???

Anyway, heres some pics of the first one. Next I will build a dual 6111 with the heaters in series powered off my 12.6 custom regulated wall wart.
(Needs a stompin switch, gotta order some)

(http://i23.photobucket.com/albums/b353/getpunched/DSC_0001.jpg)
(http://i23.photobucket.com/albums/b353/getpunched/DSC_0003.jpg)
(http://i23.photobucket.com/albums/b353/getpunched/DSC_0002.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on March 13, 2008, 02:52:18 PM
Sounds good and bright!  Did you mod it to get it to be more trebbly?  Mine sounds more warm which work really well with rig.

The reason why it sounds bright is that I have the tone control all the way on the treble side, and I've got a Jensen P8R (8") in my amp. The recording is done on a digital Boss recorder - that too makes things brighter than normal.

Edit: Nice shots there Forsakenrider. Welcome to the forum.  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 13, 2008, 07:47:37 PM
forsakenrider and culturejam, welcome in the VALVECASTER fan club...I made one a month ago, but still it has some issues, mainly it has that "unregulated power" hiss...That annoys me so much, I have to put a 7812 inside that box...So up till then, no recordings or official pics

Kristian, nice sample track here... :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on March 13, 2008, 07:59:06 PM
Dear Renegadrian, Check out this link: http://www.dxing.info/equipment/wall_warts_bryant.dx . Build it with a LM317 with a heatsink and you adjust your power output via trim pot and its got enough filtration for most applications. (It was literally night and day when I added it) Cheap and simple.
also, Have you tried changing any resistor values for higher gain? It sounds awesome when I crank the volume and gain to 10, but id like to be able to go past that and turn it down a bit as well...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: soulsonic on March 13, 2008, 08:00:34 PM
I traced another low-voltage tube circuit recently.
http://www.diystompboxes.com/smfforum/index.php?topic=66061.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 13, 2008, 08:11:08 PM
quote forsakenrider
Dear Renegadrian, Check out this link: http://www.dxing.info/equipment/wall_warts_bryant.dx . Build it with a LM317 with a heatsink and you adjust your power output via trim pot and its got enough filtration for most applications. (It was literally night and day when I added it) Cheap and simple.
THANKS MY FRIEND, IT SEEMS A VERY USEFUL LINK!!!

also, Have you tried changing any resistor values for higher gain? It sounds awesome when I crank the volume and gain to 10, but id like to be able to go past that and turn it down a bit as well...
NOT FOR NOW, I JUST MADE THE VERO VERSION I LAYED OUT THAT YOU CAN FIND SOME PAGES AGO, I PUT SOCKETS FOR R1 AND R2 - I NEED THE OTHER PARTS. (I'LL GO BANZAI IN A COUPLE OF DAYS...)



Also, I was messing around with my Valvecaster, my "Stratoblastered" guitar and an AMZ mosfet booster - for now using the two boosters with the Valvecaster leads to horrible sound and too much distortion...I'll try again as soon as I will have a quiet V. per se...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on March 14, 2008, 01:11:14 PM
Changing R1 and R2? Raising R1 above 1meg? Ive always seen it at 1meg in all the tube amp circuits. and raising R2, wont that lower the plate voltage? how does that increase the gain?

Another question i have is about the pots. Gain and Tone are not connected to ground in the layout but in the schematic they are, why is this?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: guitarx on March 16, 2008, 10:41:11 AM
Hi All!

I have viewed this topic some days, this schema is very cool, but I never find with change this schema for one clean sound, it is possible? how?
The clean sound would like a "preamp tube clean". Because, when "Gain" control is decrement in original schema, still have a little overdrive.

Thanks for all, sorry for my beginner question.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on March 16, 2008, 07:22:47 PM
guitarx: replace the 100k resistor with 47k. Replace the 220k resistor with 100k.
Beautiful cleans  :)

To fellow Valvecaster experimenters -- I've currently got this circuit on a breadboard, switching out everything and I have some items of interest to report, especially for those looking for more gain.

The nicest clean sound I've found so far, is with the following mods:
R2 = 100k
R3 = 47k
C1 = 0.1uf
Remove C4 and VR2

These changes gave a more honest clean sound than the original -- less distortion, better bass response and still adding the tube's character without too much change to the original clean tone. Increasing the gain brings in a light breakup that I really dig.

The nicest high gain sound I've found is from adding clipping diodes to the above mods. Two 1N34a Ge diodes with two 1N4148 Si diodes. I'm too much of a n00b to know the naming for clipping setups, so I'll just draw it in ASCii art :D
Code: [Select]
OUT        Ground
  |          |
  |---->|----|      Ge
  |----|<----|      Ge
  |          |
  |---->|----|      Si
  |----|<----|      Si


I tried a heap of different combos of those two diodes in symmetrical and asymmetrical configurations, the above setup sounded the best so far. I still have some other Si types, schotkies(spl?) and MOSFET clipping arrangements I want to try.

Introducing the Ge diodes caused a big drop in output volume, so I've added a JFET gain stage before the output, which bought the volume up to being even with the clean version.

Tonight I will be experimenting with tone stacks -- a SWTC for the clean side and a big muff-based tone with switchable mid cut for the high gain version.

My plan for all of this is a pedal to put between my OD/dist/fuzz pedals and my modulation/delay pedals. The valvecaster responds really well to too much signal from pedals before it, so I've been using it as a dirty limiter of sorts. There will be two stomp switches -- an A/B for clean/high gain and a bypass switch. Each channel has it's own gain, tone and volume controls, with different tone stacks. All sharing the one tube, and all fitting in a BB enclosure. I've already laid it out and it'll fit nicely, I just have to decide on component values to get the sound I'm looking for. I envisage this staying on all the time in clean mode, then being switched to dirty mode to provide a second channel for single channel amps. Currently I use a catalinbread hyperpak for this, but this pedal is well on it's way to achieving a better sound.

All just my uneducated opinion, based on my gear, of course ;)

EDIT: all of the above is with a 12v power supply
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 16, 2008, 09:00:39 PM
Andrew, you are great!!! I  want to experiment more on the Valvy, I already made the vero version I developed with sockets for R1 and R2, and ordered the other bits I was missing...With some different values GAIN pot...
I'll report my results...Please tell me more about the high gain channel, or how to obtain its highest gain...
It would be great to develop a kind of table with different uses (low gain, clean boost, high gain, ecc) and with sound samples...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on March 16, 2008, 09:42:56 PM
Adriano - thanks, it was for you that I posted about high gain; I know we've both been chasing that since seeing this circuit  :icon_twisted:
I'll report back when I've played with other clipping options some more, but to my ears the distortion is much more usable when generated by diode clipping and a gain recorvery stage rather than swapping resistors in the circuit.

Swapping out C1 for something larger helps add some more of that "chug chug" high gain -- but this circuit doesn't do the modern metal sound. I'm currently using 0.1uF, but tried up to 1.5uF film cap. It got too mushy with the 1.5uF.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 20, 2008, 12:15:39 PM
I'd like to thank Jared for the gift...I received several tubes for free...That leaves me speechless...

Needless to say I tried them all...

Here's my thoughts on using them on Valvy running  at 12V

* 12AU7 = the main choice, good. The one I liked the most was a RCA.
* 12AT7 = not bad, try one and see if you like the result...They sound good stock and I believe they could be even better with minor tweakings...
* 12BH7 = Didn't know that kind of tube...They are great to use on this project!!! They give a little more gain too, to my ears...

More on that later, my friends...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cyberk007 on March 21, 2008, 02:52:04 PM
man i built one of these and i just cant seem to get it to work, anybody think they have an idea of whats wrong?  ???
http://www.diystompboxes.com/smfforum/index.php?topic=66252.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Papa_lazerous on March 25, 2008, 08:39:58 PM
man i built one of these and i just cant seem to get it to work, anybody think they have an idea of whats wrong?  ???
http://www.diystompboxes.com/smfforum/index.php?topic=66252.0

confused as to why you would post in this thread about another thread about an unrelated post, that has already been answered  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: culturejam on March 25, 2008, 09:00:30 PM
I built one recently as well, and I really dig it.

It has a ton of hum, however, no matter the gain or volume setting.

Also, it seems to generate a noticeable octave effect, kinda like an octave-fuzz. More prominent on the higher frets and with the neck pickup.

Could this be a funky tube? I used a new JJ 12au7.

It's probably something I did wrong, but when working with tubes there is always a chance that it's the tube.  :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on March 25, 2008, 09:10:29 PM
It has a ton of hum, however, no matter the gain or volume setting.

It's definitely your build/tube, not the circuit.

Here's a sample of mine, same passage played twice -- first time bypassed, second time with gain on zero and volume at unity. There's almost no noticeable difference in sound (just as I wanted ;))

clean valvecaster sample (http://notinteractive.com/stuff/guitar/fx/t00b/clean.mp3) signal path is carvin fatboy > valvecaster > roland microcube > mbox 2 (line in)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on March 26, 2008, 06:01:36 AM
Mostly, hum = grounding issues.  Check that the signal isn't "floating", with no reference to ground, at some point.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: culturejam on March 26, 2008, 02:22:05 PM
It's definitely your build/tube, not the circuit.

Since nobody else mentioned hum, I figured it wasn't the circuit.

Check that the signal isn't "floating", with no reference to ground, at some point.

Will do. Thanks.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 26, 2008, 11:25:54 PM
It's definitely your build/tube, not the circuit.

Since nobody else mentioned hum, I figured it wasn't the circuit.

Check that the signal isn't "floating", with no reference to ground, at some point.

Will do. Thanks.

It could be your power supply.  I used a small Boss 9V and got a lot of hum then changed to the bigger Boss PS (red one) and hum was gone.  I'm trying to build a filter ckt but the cheaper / smaller transformer still produces hum.  The bigger (red) Boss supply still runs this pedal clean.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 27, 2008, 08:12:20 AM
I definitely agree with you, my Valvy has this horrible hiss, I only have unreguated PS. I gave it to my GF brother to try it, he had no hiss at all, using REGULATED PS. So I am waiting to receive those 7812s to filter the power...It seems a must, try it, after all it's just a little mod that seems to be so useful, reading others experiences in the ast pages...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on March 27, 2008, 09:09:04 PM
LM317's and this circuit will remove your hiss http://www.dxing.info/equipment/wall_warts_bryant.dx . Thats what i use and mine is dead quiet.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 28, 2008, 08:47:19 AM
Finally received that 7812 - mounted with the 100uF filter cap on the dc jack - hiss is just a memory... 8)
Now I really enjoy my Valvy!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 29, 2008, 12:31:51 AM
Glad you got the problems resolved!   :D
Did you place the 100uF across the +/- of the power leads?

I used the C1, C2, D2 from this power filter and still get the 60 Hz hum from my small wall wart.

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/psu.gif)

Maybe there's a better filter out there.  Any other recommendations?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on March 29, 2008, 08:25:15 AM
I used the C1, C2, D2 from this power filter and still get the 60 Hz hum from my small wall wart.

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/psu.gif)

Maybe there's a better filter out there.  Any other recommendations?


http://www.dxing.info/equipment/wall_warts_bryant.dx
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 29, 2008, 08:43:02 AM
Glad you got the problems resolved!   :D
Did you place the 100uF across the +/- of the power leads?

Yes, man, that was recomended some pages ago...
put a 100uF cap across the DC jack (positive leg to positive rail, neg. leg to neg. rail), then, instead of connecting the positive rail directly to the circuit, connect it to the regulator's pin1, ground to pin2, and the circuit to pin3. Then screw it on the enclosure. It is a 7812.

The caps legs are soldered directly to the dc jack lugs...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 29, 2008, 03:07:15 PM
Thanks Renegadrian, I'm going to try Forsakenrider's link using the 470uF and .1uF filter next.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 29, 2008, 03:20:45 PM
Well here's my little contribution to this awesome thread.   :D
Here's a smaller PC board for this cool little pre.  I've used it and verified that it works.  Haven't hooked up the voltage divider section but it should work too. 

The trace and components are exactly mirrored so, fold on the line and  iron the trace and components on the PC at the same time.
This is 300dpi image.

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/MatsumiTubeVertPinsTrace.jpg)

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/MatsumiTubeVertPinsTraceDetail.jpg)

Enjoy!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 03, 2008, 04:12:40 PM

* 12AU7 = the main choice, good. The one I liked the most was a RCA.
* 12AT7 = not bad, try one and see if you like the result...They sound good stock and I believe they could be even better with minor tweakings...
* 12BH7 = Didn't know that kind of tube...They are great to use on this project!!! They give a little more gain too, to my ears...


After the insertion of the 7812 in the circuit, which makes it very silent (Hell, dead silent!!!  :icon_eek:), I tried again 12BH7 - well, they hum...Maybe they'd work with some tweaking, but not this way...6BQ7A seem to act the same way (and they do light a lot!!!).
Waitin' my breadboard to arrive, I believe those two types can give a lot more...

Got my Valvy 002 completed, up and running...I used...
- my Vero layout <---(insert PROUD smiley here...)
- 2.7M for R1 instead of 1M
- 470k for R2 instead of 220k
- 7812 and 100uF DC filter
- NO tone

It seems to have some more gain...Not a high gain box, but worth this lil' change...


Here's a pic...
(http://img230.imageshack.us/img230/3972/valvecaster0020304cs7.th.jpg) (http://img230.imageshack.us/my.php?image=valvecaster0020304cs7.jpg)

Guess who inspired me in this second version?!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 03, 2008, 08:11:34 PM
Nice work, love that sparkle paint!

I'm not surprised you've left out the tone control, I have grown to hate it :( I just leave it at full all the time so it doesn't suck treble. Next mods for mine are adding an output buffer and finding a replacement for the tone control. Maybe Jack's variation of the SWTC will do the trick.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 03, 2008, 09:26:52 PM
Glad you liked it, Andrew!  :icon_wink:
Yeah, I went toneless for this second Valvy - my first Valvy still has the tone control, I think it is not so useful...Maybe I'll put a on/off switch for a fixed rate booster (mosfet maybe, or Stratoblaster) so with a trimmer instead of the pot that controls gain...Or just a resistor...
That shoud go AFTER the tube, in my lil' experience...

Now it's time to go TWIN!!!  8)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 03, 2008, 09:48:19 PM
That shoud go AFTER the tube, in my lil' experience...

I still disagree  :P  :P  :P

I'm currently playing with a greedtone OD/dist absoluytely cranked, running into the valvecaster with gain on about 3.
Holy crap. Seriously heavy!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on April 03, 2008, 10:29:00 PM
How do I add this regulator?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 04, 2008, 06:32:45 AM
man, you should read some previous post,in this very same page... :icon_wink:

put a 100uF cap across the DC jack (positive leg to positive rail, neg. leg to neg. rail), then, instead of connecting the positive rail directly to the circuit, connect it to the regulator's pin1, ground to pin2, and the circuit to pin3. Then screw it on the enclosure. It is a 7812.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 04, 2008, 12:04:27 PM
That shoud go AFTER the tube, in my lil' experience...

I still disagree  :P  :P  :P

I'm currently playing with a greedtone OD/dist absoluytely cranked, running into the valvecaster with gain on about 3.
Holy crap. Seriously heavy!

Well, I tried a Mosfet booster before and after...While the first solution overloads the tube, and the sound is just too "boomy", the second option boost the already distorted sound, leaving the tube to work at its best.
That in my lil' personal experience...Maybe the greedtone you have sounds best the way you use it... :icon_wink:

And now...I started to put the components in the vero for the Twinny...Got everything to hook up but the pots...damn...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brad on April 04, 2008, 10:51:46 PM
Hey folks!  I don't see the point of running 12AX7's at low voltage when space charge tubes were designed for that purpose and sound freakin' great while they're at it.  Run a few of these in series and you can get anything from buffer to boost to overdrive.  See ya!

(http://i137.photobucket.com/albums/q205/styrowfoam/the-huffer.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 05, 2008, 07:51:06 AM
Hey Brad, that seems so interesting...Does it work well??? Gotta add it to the "gotta build it soon" list... :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 05, 2008, 08:06:30 PM
http://www.matsumin.net/diy/jisaku2/Valve_Caster/index.html

I'd really love to say ARIGATO to this man...Tht's the original page...Again, thx to Dano for his rendition...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 06, 2008, 02:43:27 PM
I just ordered a 6111, and am thinking of powering a Subcaster from two 9v batteries in series - anyone know what difference this will make to the sound and any changes I may have to make to the circuit?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on April 06, 2008, 03:08:50 PM
Tranceracer: That's a very nice layout. Thanks for sharing.

Everyone: I made a valvecaster for a guy, and he complained about getting in russian radio (those radiowaves really travel far) when using it with certain amps (but not his Boogie). Not that russian radio is such a bad thing, but it's not cool when combined with guitars... Is this an example of microphonics or is it something else ? Should there be some sort of RF filtering in this circuit to prevent this kind of thing happening, or would putting the tube INSIDE the box make all the difference ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on April 06, 2008, 03:23:04 PM
Put a sheild on the 12AU7.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on April 06, 2008, 03:25:00 PM
Done that of course. Doesn't help.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on April 06, 2008, 05:47:56 PM
Tranceracer: That's a very nice layout. Thanks for sharing.

No problemo my pleasure!   :D

getting in russian radio (those radiowaves really travel far) when using it with certain amps (but not his Boogie). Not that russian radio is such a bad thing, but it's not cool when combined with guitars... Is this an example of microphonics or is it something else ? Should there be some sort of RF filtering in this circuit to prevent this kind of thing happening, or would putting the tube INSIDE the box make all the difference ?

Does the radio interference still happen when the box is bypassed?
Does it still happen when you turn the box 90 degrees?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 06, 2008, 05:53:58 PM
Hey Kristian, you made a regen, didn't ya?!  :icon_lol:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on April 07, 2008, 04:58:17 PM
Just a thought - can anyone think of a 12V tube preamp (space charge tubes, maybe?) that will be clean enough to be used as a microphone preamp?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 07, 2008, 06:34:00 PM
I haven't changed the Valvy components to go cleaner...Others reported it can be a good clean booster with those changes...
Otherwise, maybe the huffer (see previous page) could do the job, but again I don't know personally...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 08, 2008, 10:30:39 AM
Got Valvy-addicted...I just can't stop playing thru this nice lil' box...
My fav tunes (the one this box fit well to my ears) are Whole lotta Rosie, Perfect Strangers, Demon's Eye, Black Dog, Hair of the Dog, Stargazer, Say what you will, Ready an' Willing, Gypsy Road...And the list could go on...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on April 08, 2008, 03:00:48 PM
I just ordered a 6111, and am thinking of powering a Subcaster from two 9v batteries in series - anyone know what difference this will make to the sound and any changes I may have to make to the circuit?

Dear frequency. I personally love 6111's and have build many headphone amps and hifi equipement with them. Youre double 9 vold is good in one sense... the tubes love more voltage... but you will need to regulat the heaters to 6.3 volts. the tubes do not like more or less. Then by adding a regulator you will lose a lot of your power through heat, thus eating batteries for dinner.

Try a 24volt wall wart with a regulator for the heaters and youre rockin'.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on April 08, 2008, 03:02:13 PM
Hey folks!  I don't see the point of running 12AX7's at low voltage when space charge tubes were designed for that purpose and sound freakin' great while they're at it.  Run a few of these in series and you can get anything from buffer to boost to overdrive.  See ya!

(http://i137.photobucket.com/albums/q205/styrowfoam/the-huffer.gif)

But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 08, 2008, 03:06:19 PM


Quote
But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay


http://www.tubesandmore.com/ (http://www.tubesandmore.com/)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 08, 2008, 04:02:33 PM
forsakenrider - i would love to see more schematics using the 6111 - particularly hifi - do you have any? Thanks
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 08, 2008, 08:33:02 PM


Quote
But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay


http://www.tubesandmore.com/ (http://www.tubesandmore.com/)

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=160227370765

Yes, maybe they aren't easy to find like the ol' 12A*7 family, but hey just browse a little... :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on April 09, 2008, 02:25:07 AM
I think the spirit of this li'l project is to use a tube that's relatively easy to find and works well in this application.  I was able to go down to my local guitar shop and pick up two 12AU7 on my way home from work.

I guess the next step is to move into more esoteric stuff to find that magic tone eh?   :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 09, 2008, 06:17:48 AM
Yes, the TUBE ALCHEMY!  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on April 10, 2008, 03:32:27 PM
A couple of quick questions...

1) Should the 1uf capacitors negative leg be leading into the circuit or into the tone pot in the Beavis schematic?

(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCaster.gif)

2) Has anyone built and verified the original Matsumin valvecaster layouts? might be cool to have a PCB version of this too.

(http://chawk.files.wordpress.com/2008/04/trurl_pagecontent2.jpg)
(http://chawk.files.wordpress.com/2008/04/trurl_pagecontent-12.gif)
(http://chawk.files.wordpress.com/2008/04/trurl_pagecontent2.gif)

Thanks.

Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on April 10, 2008, 09:07:29 PM
(http://www.faqs.org/docs/electric/DC/00301.png)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 10, 2008, 09:32:52 PM
Matt, regarding your first question - I used a non polarized cap, it works great...
And, no I haven't tried the original Layout (not yet...)

Also I remember someone suggested the use of a SHO to fatten its sound some pages ago...I just built it one myself...
Well, my two Valvies seem to sound worse with something before/after them...Even if the SHO is quite good played alone, it just won't fit that well with the Valvy, even with the gain at its middle position...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on April 11, 2008, 10:59:57 AM
Thanks for the responses guys...

Bummed though because I tried it both ways and with a non-electro and it still isn't working... back to the lab I guess.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: TELEFUNKON on April 11, 2008, 01:15:26 PM
Thanks for the responses guys...

Bummed though because I tried it both ways and with a non-electro and it still isn't working... back to the lab I guess.



Is your pinout of the tube correct?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on April 11, 2008, 03:17:06 PM


Is your pinout of the tube correct?

That is a good question... I actually ended up using an ECC802 but from what I've read they are identical to the 12AU7. I'm using a valve socket and it really only fits in one way. I'm stymied. works fine in bypass mode. when engaged I hear noise and when the strings are touched it sounds like a ground issue. everything seems to be wired up ok. probably just a matter of going over everything again.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Caferacernoc on April 11, 2008, 04:28:35 PM
Just a thought - can anyone think of a 12V tube preamp (space charge tubes, maybe?) that will be clean enough to be used as a microphone preamp?


If you build a Valve Caster and change R2 and R3 to 50k it would clean up nicely. That's with a 12au7 tube. The space charge 12u7 has a bit less drive and would be a little cleaner than that.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: puretube on April 11, 2008, 05:46:47 PM
TopView/BottomView... (http://www.diystompboxes.com/smfforum/index.php?topic=35105.msg284887#msg284887)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 11, 2008, 09:13:11 PM


Is your pinout of the tube correct?

That is a good question... I actually ended up using an ECC802 but from what I've read they are identical to the 12AU7. I'm using a valve socket and it really only fits in one way. I'm stymied. works fine in bypass mode. when engaged I hear noise and when the strings are touched it sounds like a ground issue. everything seems to be wired up ok. probably just a matter of going over everything again.

Matt, I believe that is a typo, you meant ECC82. you know us and europe have 2 different way to mark tubes, so an ECC82 IS a 12AU7.

If  you got a lil' piece of vero around, I'd suggest to go with that PERFECT layout (guess who drew it?!  8)) that I personally used and is tested, verified and guaranteed...
http://img361.imageshack.us/my.php?image=valvecasterv05sv9.jpg
http://img245.imageshack.us/my.php?image=valvecasternotoneog3.jpg

Else I'd have to come there and take a look (and  my gf would be so happy, she lived there for some months and just love NYC, also our love story begins there, but I don't want to get you bored telling you all the story...)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: forsakenrider on April 13, 2008, 10:24:03 AM
http://www.eurotubes.com/euro-e.htm
Some info on tubes from some SUPER awesome guys.
they only sell JJ tubes but matt is right, the EC802 is a 12au7 or ECC82 variant. But it should definitely work.

Any pics matt? maybe one of use with a working valvey can spot the issue? also, what are you using for power?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on April 14, 2008, 01:30:33 AM
Tried a clean mod today - replace R2 with a 100k resistor and R3 with a 47K. It clean out nice, but not entirely. It works pretty nice on an acoustic guitar miced with an electret condenser microphone (battery powered), but the circuit itself is too noisy to get an actual usable result (hiss/buzz - maybe RF - that is very apparent when the signal is amplified enough to get a usable signal from the microphone, especially if I run an LA-light compressor after it). Any thoughts? Filter caps, maybe?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Salvatore on April 14, 2008, 06:49:57 AM
Just a thought - can anyone think of a 12V tube preamp (space charge tubes, maybe?) that will be clean enough to be used as a microphone preamp?


A low voltage mic pre would be godsend, but to get the amplification/sig to noise ratio right, I suppose you can´t get around space charge tubes.
Don´t know if it´s a good idea, but I found this overdrive schematic running from 9 volts AC (upped to 48 volts, so it might double as phantom power as well).
It uses a (very cheep, around 2 bucks) low voltage pcf802 tube, it might be transformed in a mic pre by putting 2 in series and tinker with it ?

http://www.tubepower.de/german/main_de.html
http://www.tubepower.de/pictures/projects/RTD-1-Live-schematic.jpg
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Chawk on April 14, 2008, 10:30:40 AM
http://www.eurotubes.com/euro-e.htm
Some info on tubes from some SUPER awesome guys.
they only sell JJ tubes but matt is right, the EC802 is a 12au7 or ECC82 variant. But it should definitely work.

Any pics matt? maybe one of use with a working valvey can spot the issue? also, what are you using for power?


No pics yet... I finally got this thing up and running over the weekend (thanks to Adriano's vero layout). The tube I ended up using was a ECC82. I was attempting to make this for a combo pedal coupled with a Dist + but the two didn't seem to like working with each other to my ears. Combining the two lost a bit of what makes the Valvecaster so nice with the warm smooth overdrive. I seem to think that a good combo might be more along the fuzz side I'm gonna keep experimenting to see what sounds the best. Thanks for everyone's help in getting this running! I'll let you know what I come up with.

Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 14, 2008, 02:13:43 PM

No pics yet... I finally got this thing up and running over the weekend (thanks to Adriano's vero layout).
Matt

Happy it worked out right, I told ya!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: juancra on April 14, 2008, 07:52:00 PM
Hi!

I'm about to start building this awesome proyect, and want to ask a few questions to assure myself that i'm not going to waste any 12ax7 or other precious tubes in it :P. I readed the entire post about a hundred times and couldn't figure out what is the best voltage / tube config. I understad that when effect is used at 9v the 12au7 is the best choice, but what is the best when powering at 12v? Do I need to change any component value to drive it at that particular voltage?

I was also thinking about the possibility to add a "clipping module" to the stock configuration. Let's say I put on the pcb various tipes of clipping  diodes (leds, GE, Si and the like) and select them through a rotary switch. It would be possible? I though that I could add another small cheap tube configured as a clipping diode to make it a even more massive proyect. Could this be possible?

Thanks for anyone who could help me, I always have too much ideas but less knowledge to carry them on.
Sebastian
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 14, 2008, 08:13:02 PM
Sebastian, I built 2 of them - they are intended to work at 9V or 12V, I prefer the second. Some hiss remains from DC and a voltage regulator is a good solution to make it deadly silent. As for the valves, 12AU7 is the main choice while 12AT7s work good too. 12AX7s just sound boomy...Not a good choice at all.
Whichever voltage you'll use, you don't have to make any change in the components, just the voltage regulator (7812 for 12V or 7809 for 9V)
You may want to change some components that change a bit its sound, but again it's your choice, may you need a cleaner box or a good overdriven sound. Tone control - I got rid of it, found it not so useful...Again, you decide...
As for the clipping module, haven't tried it yet, so you can be the pioneer and report your experiments here!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 14, 2008, 08:42:22 PM
juancra: I've also built a couple and much prefer 12v. I was getting a lot of hum using old RCA 12AU7s at 9v, but even with a brand new JJ valve it sounds better at 12. I'm not using a voltage regulator as I get no noise from my power supply.

re clipping diodes, I have tried symmetrical and asymmetrical configurations using various Si diodes, Ge diodes, red/green/yellow LEDs and mosfets. None of them resulted in a more musical/pleasing sound than the standard valvecaster. I also tried adding a JFET gain stage before the clipping diodes and/or a mosfet boost after and found that while it managed to bring the clipped signal up to the same volume as the non clipped signal, it was mushy and a little noisy (especially on the breadboard!). Another thing I tried was an EHX Muff Fuzz between the tube and the tone stack.

All of these experiments were interesting, some more usable than others, but all made "just another distortion" that to my ears was no better (and usually worse) than other distortion circuits that don't use a valve. All of the various experiments lost the mellow/warm drive that makes the valvecaster a fun circuit and either made it a mushy distortion or thin and crappy if smaller caps where used to reduce bass.

I don't want to discourage you from experimenting, just trying to pass on what I've already tried :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on April 14, 2008, 08:52:32 PM
Hi
Quote
either made it a mushy distortion
you might find that it helps to lower the value of the grid-to-ground resistor.  220k to 470k are good values.  1M is probably too high.  Higher values "store" super-low frequency charge on the grid.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: juancra on April 14, 2008, 09:06:09 PM
Andrew and Adrian!

Thanks a lot for your quick response! I thought about adding the diode clipping to make this proyect more " interesting"  to me 'cause it's the first serious proyect for my pedalboard and I wanted to have more "flavors" of it more than just a tone boost . With this new info I'm not sure if I will carry on with that mod, I think I'll just add a booster (don't know exactly which) before or after the effect and that will be all. About the hum issues Adrian found, I'll make a pcb that has the placements for the filtering portion. If it hums with my wall wart, i'll add what's necessary. Talking about tubes, I'm about to purchase a new Sovtek 12AU7, Is that a good tube brand?. How can I assure the tube is new?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 14, 2008, 09:22:25 PM
you might find that it helps to lower the value of the grid-to-ground resistor.  220k to 470k are good values.  1M is probably too high. 

Thanks for the tip Brett :) I probably should have mentioned that I had already replaced that resistor with a 470k ;)

juancra: There are sooo many bargain 12AU7s on eBay. No need to get new ones, the old ones are probably better. Just make sure they state in the auction that they've been tested and stick with a seller who sells a lot of tubes if you're uncertain.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 14, 2008, 09:52:17 PM
I totally second what Andrew wrote... :icon_wink: I tried my Valvies with a SHO and with an AMZ Mosfet Booster, both before and after, and with my on board Stratoblaster. What they add to the sound is not that great for me, going from "uhm, okay" to "Hell, no!!!"  :icon_evil:

Seb, about the hiss I wrote...I have non regulated wall warts, and that simple mod gave me a deadly silent circuit...just the 3 pin regulator and a electrolytic on the power jack...that's it!!!  :icon_cool:

And as for the tubes, I went shopping on Evilbay  :icon_twisted: this past week, I got 8 Sylvania for $32 shipped to Rome IT, it's like 2.50 Euros each...nuff said...

Also, I'd suggest you to try some different brands, each one I tried has its own character...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: juancra on April 15, 2008, 09:44:53 AM
After all this talking you guys convinced me to go for the easy money and just build the valvy "as is". I will only add the filter section.

Regarding tubes, Here in south america we don't have Ebay, we have MercadoLibre, who has a "non-agression pact" with Ebay, but it is also a jungle.. Every time im about to buy something I think i'm going to get a plastic empty box :S .. :P, but I think i will go for a Toshiba 12AU7 for 10$ and pray for everything to go OK :D

Once again, I must say you guys at Diystompboxes rules!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 15, 2008, 10:10:12 AM
I was wondering if it is necessary to let the preamp tube to warm-up before applying the plate voltage (even if it is around 12V) in order to extend their life? Or is it more a concern for power amp tubes, or tubes that run at "regular B+ voltages" (200V and +).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 15, 2008, 01:29:27 PM
Saw this t-shirt on eBay - made me laugh! And no, its not my auction - I'm in the UK

http://cgi.ebay.co.uk/Rare-12AU7-Twin-Triode-Tube-T-Shirt-True-Geeks-Only_W0QQitemZ150234662850QQihZ005QQcategoryZ48710QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ItZaLLgOOd on April 15, 2008, 04:04:21 PM
I lost track after the first 8 pages but has anybody tried a tone stack instead of just a tone control?  If so what were the results?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on April 15, 2008, 04:10:08 PM
I imagine it wouldnt be all that great....probbly less gain/output.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 15, 2008, 04:13:45 PM
In my little Valvy experiments, I removed the tone control...I just feel that the GREAT tone that comes out of the tube is well worth left unprocessed tonally speaking...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 15, 2008, 04:23:43 PM
I was thinking of trying one of these:

http://www.tube-town.net/diy/tt-sam/tt-sam-sch01.JPG
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 15, 2008, 04:25:30 PM
..................specifically the tonestacks with the valvecaster (not the amp)!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 15, 2008, 07:46:52 PM
I lost track after the first 8 pages but has anybody tried a tone stack instead of just a tone control?  If so what were the results?

I tried a big muff tone stack. Not impressed. For me, this circuit needs midrange punch, and gets even more from removing the tone control entirely.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on April 15, 2008, 08:17:09 PM
I was wondering if it is necessary to let the preamp tube to warm-up before applying the plate voltage (even if it is around 12V) in order to extend their life? Or is it more a concern for power amp tubes, or tubes that run at "regular B+ voltages" (200V and +).

I'm not sure if pre warming tubes at this small voltage will extend the life that much but I did notice that as my 12AU7 pre warms up the overdrive tone actually gets less grit (which I like) and gets a little smoother.  My GT 12AU7 seems pretty steady but some other tubes' character changes a little as they warm up.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 16, 2008, 06:57:37 PM
I know it is a complete different circuit from the boosters I tried to couple with the Valvies, but I had to report that the 3dB gain of the Tillman Preamp are a nice add, it clears the sound a little too, and it doesn't get boomy at all, so let me suggest you this...

PUT A TILLMAN PREAMP BEFORE A VALVECASTER!!!

After all, it's just a simple circuit, so you can just try...But I believe it won't disappoint you...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on April 17, 2008, 05:57:38 AM
I lost track after the first 8 pages but has anybody tried a tone stack instead of just a tone control?  If so what were the results?
    Try a Baxandall and a source follower. I haven't tried it, just a hunch.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripdivot on April 17, 2008, 01:52:59 PM
The Baxandall has a lot of loss and will eat up quite a bit of signal.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 19, 2008, 01:42:09 PM
First time i've ever tried a tube project.
I do have a ECC85 and in a bit unsure as if i should treat it as an replacement for the 12au7.
I've been looking at some data sheets and i found that the only diffrences are the heater current wich is a bit higher on the ECC85 and the absence of the center tapped heaters. Have i missed something or could i just pop it into this circuit?

http://www.radiomuseum.org/tubes/tube_ecc85.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: juancra on April 19, 2008, 05:55:32 PM
ECC type tubes are "cousins" of the american made 12a_7 family. You can use that one in this proyect.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 19, 2008, 07:38:32 PM
From the http://www.nj7p.org/ site...

12AU7
Heater Voltage ................................ 6.3/12.6 V
Heater Current ................................ 0.3/0.15 A

ECC85
Heater Voltage ................................ 6.3 V
Heater Current ................................ 0.435 A

Also, ecc85 is missing the 9 pin heater connection...Also, thee heaters cannot work on 12V but only in 6V???
Anyway some ecc's stand in the 12a*7 yes, (in fact ecc82 is the equivalent for our 12AU7) but for what I read this ecc85 is not part of that family...Dunno if thie ecc85 can work in this circuit, but just try it out man...After all, if your first tube isn't the best, you can easily get a bunch of ol' 12AU7/ECC82 for so little $$ on ebay...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 20, 2008, 10:55:44 AM
Sure thing, will do.
Just thought i'd ask in case i missed something. thanks for the replys.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on April 21, 2008, 12:01:20 AM
The Baxandall has a lot of loss and will eat up quite a bit of signal.
  Exactly, that's why you need the source follower.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on April 22, 2008, 09:18:46 AM
  Keep it simple. An N-chan JFET, 10k resistor, and a .1 output cap.
  Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 23, 2008, 01:22:24 PM
I tried building this although i got a problem.
My heaters run at full voltage (9.0 from pin 5 to 4).
I got pin 5 directly connected to R2 (220k) on the opposite side of pin 1 on the tube socket, is that the problem?

I skipped the tone controll and the only substitutions are a film cap for output cap and an ECC85 as tube (not put in when messuring voltages).

(http://i269.photobucket.com/albums/jj42/Albot1/222.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 23, 2008, 03:40:09 PM
Albot, R2 is between pins 5 and 1 - that is correct...So the problem is somewhere else...Maybe the ECC85 we were arguing about...maybe you should stick to the tubes that are guaranteed to work (12AU7 and 12AT7) and experiment later on...
A silly question...Did you try to run it at 6V?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 23, 2008, 03:43:43 PM
But am i supposed to read 9v between pin 4 and 5 with no tube in? I do.
I tried to start it up fist on 9 v and the tube lit up quite yellow quite like a light-bulb so i quickly turned it off and then accutlay tested it with 6v just to see if the heaters survived the light-bulb experience,  it seems like they did
Didn't try to hook it up to an amp though.. maybe i should?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 23, 2008, 04:00:39 PM
But am i supposed to read 9v between pin 4 and 5 with no tube in? I do.
ACTUALLY I REALLY DON'T KNOW...BUT YES, I BELIEVE...9V HAS AN ENTER AND AN EXIT POINT IN PINS 4 AND 5.

I tried to start it up fist on 9 v and the tube lit up quite yellow quite like a light-bulb
MAYBE THE CIRCUIT ISN'T GOOD FOR THAT TUBE, 12AU7s DON'T LIGHT THAT MUCH...

MY THOUGHT...VALVECASTER AND ECC85 AREN'T MADE TO BE TOGETHER...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 23, 2008, 04:08:08 PM
You know.. i think it is something with the heaters.. when messuring the tube pins i get pretty much no resistance (3 OHM) is there more across the 12au7 heater pins??

even at 6 v the heaters start out at red then clinmb up to a very light yellow/orange and i hear the wallwart starting to sizzle (boiling caps?) so i think it pulls current like a madman!! no idea why though.

I'd better pick up a 12 au7 soon, would be nice to know if i should have 9v across pin 4 and 5 before trying it out though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 23, 2008, 04:09:50 PM
According to ECC85 datasheets, you must have 6.3V between pin 4 & 5, not 9V.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dav_ on April 24, 2008, 11:35:45 AM
Hello from Geneva !
I build this tube boost last week and it work great  ;D
(http://images3.hiboox.com/vignettes/1608/31yqv083.jpg) (http://www.hiboox.com/lang-fr/image.php?img=31yqv083.jpg)
The box is not finish...
I used a 12au7 from electroharmonix and 15v 500mA power supply regulated by a lm7812.
And I used the “pcb-less wiring diagram” from beavisaudio, there just one error, the Gain pot is wiring wrong ;)
A little sample with my es335 guitar, I’m not a good guitar player but this is only for fun :)
http://tflash.free.fr/12au7vavlecaster12v/MIC-2008-04-15_18h11m48s.wav (http://tflash.free.fr/12au7vavlecaster12v/MIC-2008-04-15_18h11m48s.wav)
Sorry for my English this is not my language…



Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gluedtogether on April 24, 2008, 12:01:35 PM
I am trying a slight variation - single tube, 2 switches to go between clean boost and drive. I did the clean mod, changing R2 and R3 to lower values. I am putting a switch between pin  three and the gain pot. Works fairly well so far. the clean boost in not a huge volume boost as is, but does fatten the sound and provide a decent boost. then kicking the gain in has been a nice addition.

I just picked up a box so I will post picks when I am done.
here is my post on the switch- probably going to a dpdt. Was trying to use a spare spdt, but can't use that and get an led going for the second switch
http://www.diystompboxes.com/smfforum/index.php?topic=67292.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 24, 2008, 05:55:19 PM
dav, without offense,for sure, but I surely have seen better fx... :icon_confused:
Also, you mean the error on the original layout was on the tone, wired the opposite pins...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on April 24, 2008, 06:09:09 PM
For the record- I plugged an EC885 into mine and it works just fine.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on April 25, 2008, 12:19:52 AM
I have built a clean 25W stereo power amp based on a tripath chip and I'm trying to decide on a preamp for it. I would like something warm, clean and tube-like that can be made to just break up a bit with high gain. I'm wondering if one of the many variations discussed in this (LONG!) thread would fit the bill. I'm trying to cram everything in to a small enclosure so the 6111 tubes really appeal to me. I would mount two in 8-pin DIP sockets on a single board with dual-gang pots to produce a stereo preamp.  So.. given my requirement of a range of clean sounds to just breaking up "dirty" overdrive (a bluesy sound) does this seem feasable? I'm not sure if this circuit would produce enough gain to properly drive my power amp though.

Any thoughts?
Edit:
To give a better idea of what kind of tone I'm looking for my current "best choice" for a preamp is a Professor Tweed from ROG but a hybrid sounds much more appealing to me.
Also, if it helps to answer my question, the power amp I built has an input impedance of 22kOhms (but I can bump that up to 58K if I need more gain from the power amp) and is meant to be driven by a 1V RMS line level signal but can handle up to ~4V on the inputs before frying the chip.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: puretube on April 26, 2008, 02:56:08 AM
Don`t over-heat this 12AU7 (http://www.newsensor.com/ProductHighLight.aspx?ProId=1264)!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 26, 2008, 11:09:29 AM
Yes! My Valvecaster works! Just hooked it up - now I need to work on the enclosure.  :icon_biggrin:

Now if I could just get my Subcaster to work......!

Tube-Town Pepper Shredder next I think! http://www.tube-town.net/diy/lov/lov02-peppershredder.html

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 26, 2008, 05:32:25 PM
quote author=frequencycentral
Yes! My Valvecaster works! Just hooked it up - now I need to work on the enclosure.  :icon_biggrin:
GREAT! HAPPY TO READ THAT...ENJOY!!!

Now if I could just get my Subcaster to work......!

UH, DUNNO ABOUT THE SUBCASTER...CAN'T HELP...

Tube-Town Pepper Shredder next I think! http://www.tube-town.net/diy/lov/lov02-peppershredder.html
YES, SOMEONE POSTED A WHILE AGO...WOULD BE GREAT IF YOU OR SOMEONE ELSE COULD DRAW A P2P-PERF-VERO LAYOUT OUT OF THAT SCHEMATIC...


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 26, 2008, 05:43:28 PM
Thanks Renegadrian!

I built my Valvecaster on the tube socket - really easy. I don't think a perfboard is needed. I will build the Pepper Shredder the same way, its pretty much like two Valvecasters with a few mods.

I'll post some pictures tomorrow if I find time. I drilled the enclosure today - just need to fit it all in tomorrow.

Today I had fun:

LPB1 (DIY) > Valvecaster > Harley Benton GA5 (VJ clone) - Now that just rock!

then:

Valvecaster > Ruby > thru the GA5 speaker.

I'm defo going to build a combo with a Valvecaster, Ruby and 12" speaker - powered from a 9v battery!!

In fact I may even fit a Ruby in my Valvecaster enclosure and fit an extra socket for speaker out!

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: nico13 on April 26, 2008, 05:59:32 PM
I'm defo going to build a combo with a Valvecaster, Ruby and 12" speaker - powered from a 9v battery!!

In fact I may even fit a Ruby in my Valvecaster enclosure and fit an extra socket for speaker out!




Nice idea !

How do you plan to wire the Valvecaster and Ruby together: will you keep the gain and volume pots on both of them ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 26, 2008, 06:03:47 PM
I'm defo going to build a combo with a Valvecaster, Ruby and 12" speaker - powered from a 9v battery!!

In fact I may even fit a Ruby in my Valvecaster enclosure and fit an extra socket for speaker out!




Nice idea !

How do you plan to wire the Valvecaster and Ruby together: will you keep the gain and volume pots on both of them ?

At the moment its just one into the other, so two gain controls, which is quite nice - with everything up full I get serious sustain - serious feedback too! I guess ideally I would want to be able to get a clean sound, so maybe the Ruby gain should be on a switched potentiometer.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 26, 2008, 07:24:22 PM
I'm defo going to build a combo with a Valvecaster, Ruby and 12" speaker - powered from a 9v battery!!

That'll be great! ...for the 47 second life span of the battery  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 26, 2008, 07:27:15 PM
Hahaha! maybe a car battery then, they're 12v - not so portable though! Unless - hmmm.........I could rig up a power feed from the car's cigarette ligher socket!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 26, 2008, 08:36:51 PM
quote author=frequencycentral
I built my Valvecaster on the tube socket - really easy. I don't think a perfboard is needed. I will build the Pepper Shredder the same way, its pretty much like two Valvecasters with a few mods.


I KNOW RICK, I BUILT MY FIRST VALVY THE SAME WAY - I WAS ASKING FOR A LAYOUT OF THE PEPPER SHREDDER, I SAW THE SCHEMATIC BUT I AM NOT THAT EXPERT TO TRANSLATE IT TO A LAYOUT
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on April 26, 2008, 08:39:56 PM
still debugging mine :/
please take a glance at my picture and tell me if you find any errors.
I've been checkng it at least 10 times now and i think i'll go crazy sometime soon  :icon_eek:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on April 26, 2008, 09:15:05 PM
Does anyone have any thoughts on using this circuit as a preamp for my power amp?
-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 27, 2008, 07:37:30 AM
quote author=frequencycentral
I built my Valvecaster on the tube socket - really easy. I don't think a perfboard is needed. I will build the Pepper Shredder the same way, its pretty much like two Valvecasters with a few mods.


I KNOW RICK, I BUILT MY FIRST VALVY THE SAME WAY - I WAS ASKING FOR A LAYOUT OF THE PEPPER SHREDDER, I SAW THE SCHEMATIC BUT I AM NOT THAT EXPERT TO TRANSLATE IT TO A LAYOUT

Ok, I will post my layout based on mounting the component onto the sockets once its completed - give me a couple of weeks though!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 27, 2008, 07:39:23 AM
Does anyone have any thoughts on using this circuit as a preamp for my power amp?
-Matt
I would think this circuit would make a perfect preamp for your power amp!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 27, 2008, 08:43:19 AM
quote author=frequencycentral
I built my Valvecaster on the tube socket - really easy. I don't think a perfboard is needed. I will build the Pepper Shredder the same way, its pretty much like two Valvecasters with a few mods.


I KNOW RICK, I BUILT MY FIRST VALVY THE SAME WAY - I WAS ASKING FOR A LAYOUT OF THE PEPPER SHREDDER, I SAW THE SCHEMATIC BUT I AM NOT THAT EXPERT TO TRANSLATE IT TO A LAYOUT

Ok, I will post my layout based on mounting the component onto the sockets once its completed - give me a couple of weeks though!

that would be great, I wait  to see it!!! Thank you Rick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on April 27, 2008, 09:47:06 AM
Does anyone have any thoughts on using this circuit as a preamp for my power amp?
-Matt
I would think this circuit would make a perfect preamp for your power amp!
Thank you. I think I will give it a try. I'm building a tiny 25W stereo amp that runs entirely on 12V DC so this circuit will fit nicely. The entire thing (minus the power brick) fits neatly into a 6" x 3" x 2" enclosure. When I'm done I'll post some pics and hopefully some sound clips.

Here's another question though... If I were to build two of these preamp circuits (one for each channel on the power amp) would it make sense to use half of each tube in each of the channels to help maintain the same gain characteristics on each channel? I know some of the tube vendors will "match" tube pairs for a fee, but would this be a better solution?

For example, "Tube 1 side A" and "Tube 2 side A" would be used as the first and second gain stages for channel 1 while "Tube 1 Side B" and "Tube 2 Side B" would be used for the channel 2.

Am I simply making things more difficult for myself with no real gain? (no pun intended).
-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on April 27, 2008, 10:47:40 AM
Hi there,

I just finished a Pepper Shredder.
I used the 12U7 tubes, which are specially designed for 12 volt DC (in car radio's)
I like the sound of it very much.
It has a good amount of distortion.
I also placed a Fenderish Tonestack in the end before the volume.
Also some of the capacitors were changed for a "fatter" sound.
You have to use a good regulated power supply for this, otherwise you get a lot of hum.
To bad that I don't have time for a while to box it up. :icon_sad:
But anyway here are the layout and PCB for this project that I used.
If You use the PCB, scale it down to 56 percent.
I'm also planning to make a subcaster.........when I have the time for it :icon_frown:
(http://img229.imageshack.us/img229/920/6111peppershredderlayouah4.gif)
(http://img229.imageshack.us/img229/5783/peppershredderprintnr7.jpg)
(http://img74.imageshack.us/img74/3609/peppershredderju6.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 27, 2008, 11:18:19 AM
Jimmy-H:

Well done and welcome! I would love to hear some sound clips of the Pepper Shredder if you have time. Have you tried it with 12au7's too?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on April 27, 2008, 11:40:51 AM
Hi,

Have you tried it with 12au7's too?
No, but what I have read, the sound of the 12U7 is a little "fuller" compared to the 12au7.
The reason could be, that the 12U7 is made for low voltage.

.I would love to hear some sound clips of the Pepper Shredder if you have time.
Oke I'll try it, but I don't know how to post sound Clips.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 27, 2008, 03:16:20 PM
A few photos of my Valvecaster - this one I built to drive my VJ clone harder so I didn't feel the need for a stomp switch, the enclosure is so small it wouldn't fit anyway.
(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0085.jpg)
Want to make your tubes glow brighter? I fixed a red LED in the centre of the tube socket.
(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0086.jpg)
Here it is!
(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0087.jpg)
And in low-light conditions:
(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0089.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 27, 2008, 06:49:38 PM
Jimmy-H, your layout is so much appreciated, so thank you!!! Nice job!!! Wait for some more info (how much gainy is that fx?) and possibly some sound clips!!!
Rick, your valvy turned out great...I love that kinda finish...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Pushtone on April 27, 2008, 07:38:18 PM

I've been thinking a lot about the Valve Caster's two stages and where a two band EQ would work.

I applied the AMZ JFet buffer and Dual Tone control circuits and spliced them into the Valvecaster.

The Zed Caster has the buffer and tone circuit up front.
The Lab Caster has the buffer and tone in between the tube stages.

(http://www3.telus.net/public/david65/pedal-pics/valvecaster/ZedCaster.gif)


Never done this before. How do they look?
Are they both viable circuits still?
Which one would be most successful?

Dave




Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on April 27, 2008, 08:18:23 PM
Hi
I think it would be safest to put a buffer (JFET makes sense) at the end, before the 100k volume pot.  Otherwise, the impedance of the load might be too low for the seond valve stage.
cheers
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on April 28, 2008, 05:16:10 AM
Hi there,

The Pepper Shredder has plenty of gain.
An other idea is to leave the Tonestack, and then make a input cap selector (just like the Orange amps).
Then you have a more powerfull sound.

But I found some sound samples of the Vanilla Drive and the Pepper Shredder.
The Vanilla Drive is a little milder.
(According to the designer, the Vanilla drive can be used as a clean booster to a mild overdrive)
The tubes he used are 12AU7 from Electro Harmonics.
Here is the link : http://www.tube-town.de/ttforum/index.php?topic=7797.0
Only it's in German, but what the hack, so is the design

The Layout I posted has dissapeared, strange.
But here is it again:
(http://img233.imageshack.us/img233/1038/6111peppershredderlayoutc2.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 28, 2008, 05:31:46 AM
Ok, having built my Valvecaster I am now completely obsessed with vavle FX. I woke up this morning with the idea of an all tube multi-FX board going round my head. I think it would include:

1. a Valvecaster
2. part of The Tone God's tube tremolo
3. tube reverb (should be easy to adapt the VC to do this)
4. a tube based phaser - not sure if this one is possible???

Imagine: 4 stompswitches, half a dozen or more valves..........ooh! Any thoughts or ideas?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 28, 2008, 05:44:34 AM
ooh! Any thoughts or ideas?

http://www.puretube.com/
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 28, 2008, 05:56:43 AM
JimmyH, I read more on that forum...Some babel translation and it's more readable!!!
The pepper sounds good!!! Gotta build this one...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 28, 2008, 03:00:52 PM
ooh! Any thoughts or ideas?

http://www.puretube.com/

Looks great - but no schemos!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ambulancevoice on April 28, 2008, 05:36:04 PM


I'm defo going to build a combo with a Valvecaster, Ruby and 12" speaker - powered from a 9v battery!!


your not going to power both of them with one 9v battery? cause that wont do very well
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 28, 2008, 06:30:36 PM
OT
Andrew, is the guitar on your avatar one of yours? Are you left handed?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on April 28, 2008, 08:05:00 PM
OT
Andrew, is the guitar on your avatar one of yours? Are you left handed?

Yes and yes  -- it's a Carvin Fatboy (https://www.carvinguitars.com/carvinworld/catalog/guitars/index.php?model=hf2), but with a walnut neck and mahoganhy+quilted maple body. Highly recommended  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 29, 2008, 02:03:14 AM
Hey I'm a southpaw too!!!  :icon_surprised:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on April 29, 2008, 04:43:38 AM

4. a tube based phaser - not sure if this one is possible???


Anything is possible. But keep in mind that a phaser incorporates 5 ic's (Small Stone). Each of them includes 11 transistors and 6 diodes. Now imagine doing what that little CA3080 does, only with tubes - times 5. A tube phaser would be fabulous though. Maybe there is another way ? :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 29, 2008, 10:49:22 AM
I just uploaded a pdf file of a tube preamp, you can find it HERE (http://www.aronnelson.com/gallery/main.php/v/diyuser/6418+Tube+Preamp.pdf.html)

It's a very little and easy circuit and the 6418 is so easy to find and cheap.

Didn't build it yet, but hey it's so simple...I'll report it soon, I believe...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 29, 2008, 11:00:28 AM
Quote
I just uploaded a pdf file of a tube preamp, you can find it HERE

It's a very little and easy circuit and the 6418 is so easy to find and cheap.

Didn't build it yet, but hey it's so simple...I'll report it soon, I believe...

Pentode preamp at low-voltage? COOOOOOOOOL!!!!!!!!!!!    :icon_biggrin:

Hope it will be able to recreate the famous EF86 sound! (without the microphonics... ;))
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on April 29, 2008, 03:52:38 PM
Valvecaster sounds really good for me. Builded it yesterday with IC 7812 and ECC 82.
Sample here (http://"www.felicienne.com/extra/valvecaster.wma") : Tele -> valvecaster -> emu 0202 soundcard -> cubase.

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Berger on April 29, 2008, 03:59:49 PM
here is the dual subcaster that I've breadboarded...I'll get it in an enclosure soon, I really like it

(http://farm3.static.flickr.com/2119/2452066305_eb41f76e0a.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on April 29, 2008, 04:46:21 PM
here is the dual subcaster that I've breadboarded...I'll get it in an enclosure soon, I really like it

(http://farm3.static.flickr.com/2119/2452066305_eb41f76e0a.jpg)

Ahh....sweet glowing tubes.

Man, this thread has become a monster!

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on April 29, 2008, 05:05:03 PM
So I take it a single 6.3V power supply board (per the schematic) is sufficient to drive both heaters? I plan to use two tubes, but in a stereo configuration as my preamp stage. I bought both the 12AU7 tubes as well as the 6111's to see if there's any serious difference in gain. The 6111's will fit much better in the enclosure I plan to use, so that's what I'll build first.

-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Berger on April 29, 2008, 06:01:20 PM
Yup Dano this thread has taken off, its got me going crazy buying tubes, even better is that I'm starting to understand this stuff, and am having a lot of fun.

The only thin I notices is suppling enough amperage to the circuit for it to work right. I was using a 12volt 300ma radio shack wallwart and would get flubby sounds out of it. I switched to a 700ma power supply for work and it sounds amazing.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 29, 2008, 06:53:31 PM
Yup Dano this thread has taken off, its got me going crazy buying tubes, even better is that I'm starting to understand this stuff, and am having a lot of fun.

The only thin I notices is suppling enough amperage to the circuit for it to work right. I was using a 12volt 300ma radio shack wallwart and would get flubby sounds out of it. I switched to a 700ma power supply for work and it sounds amazing.

http://www.nj7p.org/Tube4.php?tube=6111
Heater Current ................................ 0.3 A
According to this, you need 600mA only for the heaters, am I right???

Dano, this thread is killer...Apart form the the first ones, like me,  Andrew and Kristian (krinor) I read more and more people interested in the Valvy...And the little effort in the building gives great satisfaction...You go like "WOW, i went TUBES!!!"  8)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 29, 2008, 06:57:18 PM

http://www.nj7p.org/Tube4.php?tube=6111
Heater Current ................................ 0.3 A
According to this, you need 600mA only for the heaters, am I right???


Hmmm Renegadrian - maybe you just solved my Subcaster problem - not enough mA! I guess the 317 must consume some mA too - I will try a more powerful power supply.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 29, 2008, 07:08:15 PM

http://www.nj7p.org/Tube4.php?tube=6111
Heater Current ................................ 0.3 A
According to this, you need 600mA only for the heaters, am I right???


Hmmm Renegadrian - maybe you just solved my Subcaster problem - not enough mA! I guess the 317 must consume some mA too - I will try a more powerful power supply.
Rick, if that's the case, glad I gave you a hint!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Berger on April 29, 2008, 08:03:24 PM
Also a tip I ran a 220k resistor from the vin to pin 7 and that made a huge difference on my build as well
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on April 29, 2008, 08:55:32 PM

http://www.nj7p.org/Tube4.php?tube=6111
Heater Current ................................ 0.3 A
According to this, you need 600mA only for the heaters, am I right???


Hmmm Renegadrian - maybe you just solved my Subcaster problem - not enough mA! I guess the 317 must consume some mA too - I will try a more powerful power supply.

Hi there,

You don't neet the 317 with two tubes.
Just set the heaters of the two tubes in series, the current then is stil 0.3 A.
Right?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on April 30, 2008, 04:26:14 AM
Hi Jimmy-H,
You need the LM317 of an IC 7812 to get a stable voltage on the heaters. Otherwhise you will shorten life of the tube(s).
I builded my Valvecaster with a wall wart 15V. and an IC7812, 100yF across the DC jack, pos.tip to pin 1 of the 7812, pin 2 to ground and pin 3 to the circuit.
Build the regulator on a heatsink.oh and connect only heater pins 4 and 5 of the tube.

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on April 30, 2008, 05:41:35 AM
Hi Jimmy-H,
You need the LM317 of an IC 7812 to get a stable voltage on the heaters. Otherwise you will shorten life of the tube(s).
I builded my Valvecaster with a wall wart 15V. and an IC7812, 100uF across the DC jack, pos.tip to pin 1 of the 7812, pin 2 to ground and pin 3 to the circuit.
Build the regulator on a heatsink.oh and connect only heater pins 4 and 5 of the tube.

Karsten

Yeah, your right about that ;)
But if u use good regulated powersupply in the first place, than you don't have to worry about that.
The only thing you have to do is remove the 47 E resistor in the supply filter of the subcaster.
Because of the low Resistance of the heaters.
Otherwise your voltage will drop

With tubes it's always important to have a good power supply to prevent hum.
I experienced that with the pepper shredder

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on April 30, 2008, 06:48:19 AM
yep, regulated power supply is very importent.
Builded this for my audio preamp - a little bit oversized - hahahahah

(http://www.felicienne.com/extra/netzteil01.jpg)

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Woodooman on April 30, 2008, 09:04:30 AM
Hello there

Sorry for a newbish question, but could anyone please tell me if i could use 6n1p russian 6v tubes for this project?

thanks
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 30, 2008, 09:24:02 AM
A quick glance at its details, and I believe this wouldn't be the best choice...
1) it runs on 6v, while the main tubes used here are 12v
2) it needs 600mA on heater
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 30, 2008, 09:32:54 AM
Hello there

Sorry for a newbish question, but could anyone please tell me if i could use 6n1p russian 6v tubes for this project?

thanks



The 6N1P are pre-amp tubes but are generally used as a low-power tube in guitar amplifier (see www.ax84.com  (http://www.ax84.com) for some examples), and requires about 250V on its plate (the heater is 6.3V). I don't know how it can behave in starved-mode, but it is not intended to (well, neither the 12AX7!). You can try it, but I doubt it will sound great.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on April 30, 2008, 09:44:54 AM
Try it.
This one is similar to the 12AX7, ECC 88 or 6922. You can see them in a lot of high end audio applications. For the heater you will need a regulated 6.3V.
Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on April 30, 2008, 10:03:15 AM
With tubes it's always important to have a good power supply to prevent hum.
I experienced that with the pepper shredder

Would a switching power supply be sufficient? I'm looking at this guy to power both my 25W stereo power amp and two Tubecaster preamps... http://www.mini-box.com/80w-AC-DC-Power-Adapter-12v-6-6A?sc=8&category=13

i won't bother if it will have a lot of hum.
-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Fender56 on April 30, 2008, 11:15:53 AM
Quote
Would a switching power supply be sufficient? I'm looking at this guy to power both my 25W stereo power amp and two Tubecaster preamps... http://www.mini-box.com/80w-AC-DC-Power-Adapter-12v-6-6A?sc=8&category=13

i won't bother if it will have a lot of hum.
-Matt



In order to reduce the hum from your power supply, you should look for a low line regulation value (about +/- 1% will be great). Higher this value, higher the risk of hum.

In your case, this value is not shown so it is hard to predict. I assume it will be fine (those kind of big adaptors are usually well regulated) but ask for the return policy, just in case!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: puretube on April 30, 2008, 01:41:29 PM
A switchmode power supply rather causes "whine" than "hum", IMHO...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 30, 2008, 03:18:26 PM
Just been debugging my Subcaster - again.

I can't seem to unite the voltage regulator for the heater with the main circuit. I know the voltage regulator works fine without being connected to the main circuit.

So - I thought I'd try bypassing the voltage regulator and running the whole main circuit at 6 volts.

Result - it works. Distortion, but obviously no boost as the voltage is too low.

I drove it a little harder with my LPB-1 - excellent.

Conclusions: this circuit will work at 6 volt  -with less gain.

As i can't seem to get the two parts together, I'm going to try this to get 6v for the heater from 12v:

(http://i210.photobucket.com/albums/bb292/frequencycentral/12v-6v.jpg)

The opamp can be anything really - 741, 1458, 351 etc

I've used it before to creat bipolar power for opamps and OTAs.

I will post my results.

Anyone care to comment?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on April 30, 2008, 03:47:38 PM
Why so difficult?
Just place a 100yF acroos the DC jack. The pos. leg to pin 1 of an IC7812, pin 2 to ground, pin 3 to the circuit. If you want you can place another elco (47yf) on pin 3. So you get a regulated/cheapy and nice filtered power supply.

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 30, 2008, 03:54:04 PM
Why so difficult?
Just place a 100yF acroos the DC jack. The pos. leg to pin 1 of an IC7812, pin 2 to ground, pin 3 to the circuit. If you want you can place another elco (47yf) on pin 3. So you get a regulated/cheapy and nice filtered power supply.

Karsten
That would give 12 volts at pin 3, the Valvecaster (12au7) heater is 12 volt - but the Subcaster (6111) heater is 6 volt - well 6.3 volt to be exact.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SirElwood on April 30, 2008, 06:50:44 PM
This is a EF86 preamp running on 12-24 volts. Should be interesting.

http://www.tg-music.com/EF86.pdf (http://www.tg-music.com/EF86.pdf)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: awitee on April 30, 2008, 07:01:16 PM
hi i just built the valvecaster
it seems the volume is a bit weak, it needs to be at around 3 o clock to maintain the bypass level.. is it all this way or just mine?
and i dont think the gain is enough, i used a 100k log pot besides the 50k, is it because of this?
and i feel its too bassy what mods can i apply to it?
i used a 12au7 tube running off 9v
no problem with noise
i used a booster pedal before it, and it sound great
but as a standalone.. i dont know..
can you guys pls suggest some modifications? thx!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 01, 2008, 05:25:07 AM
hi i just built the valvecaster
it seems the volume is a bit weak, it needs to be at around 3 o clock to maintain the bypass level.. is it all this way or just mine?
and i don't think the gain is enough, i used a 100k log pot besides the 50k, is it because of this?
and i feel its too bassy what mods can i apply to it?
i used a 12au7 tube running off 9v
no problem with noise
i used a booster pedal before it, and it sound great
but as a standalone.. i don't know..
can you guys pls suggest some modifications? thx!

Hi awitee,

You could try to run off 12 volt.(more headroom)
But you have to watch the heater voltage.
If you connect 12 volts to 4 and 5 of the tube, you will be alright.
With the bass thing....you can change the input cap.
I believe a smaller cap --> less bass.
Also, you can try to remove the tone-circuit or make it switchable(gives a little more gain).

success with your valvecaster!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Stellan on May 01, 2008, 06:53:09 AM
hi i just built the valvecaster
it seems the volume is a bit weak, it needs to be at around 3 o clock to maintain the bypass level.. is it all this way or just mine?
and i don't think the gain is enough, i used a 100k log pot besides the 50k, is it because of this?
and i feel its too bassy what mods can i apply to it?
i used a 12au7 tube running off 9v
no problem with noise
i used a booster pedal before it, and it sound great
but as a standalone.. i don't know..
can you guys pls suggest some modifications? thx!

Hi awitee,

You could try to run off 12 volt.(more headroom)
But you have to watch the heater voltage.
If you connect 12 volts to 4 and 5 of the tube, you will be alright.
With the bass thing....you can change the input cap.
I believe a smaller cap --> less bass.
Also, you can try to remove the tone-circuit or make it switchable(gives a little more gain).

success with your valvecaster!

+1 on the 12V. Mine was barely more than unity gain with 9V. The input cap needs to be higher to brighten the pedal. I doubled mine and that works great! It is still "warm" sounding, but now you go from smooth dark tone to somewhat transparent eq with the toneknob. Try it, I really like mine now! I dont get overdrive without hitting it with a booster, but i also have low signal pickups on the relic strat i used it with. Have yet to try it with humbuckers. I think I will end up putting a booster in there with it just because i get GREAT sounds with my Tubescreamer set to minimum gain into the Valvecaster.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: awitee on May 01, 2008, 07:35:13 AM
hi i just built the valvecaster
it seems the volume is a bit weak, it needs to be at around 3 o clock to maintain the bypass level.. is it all this way or just mine?
and i don't think the gain is enough, i used a 100k log pot besides the 50k, is it because of this?
and i feel its too bassy what mods can i apply to it?
i used a 12au7 tube running off 9v
no problem with noise
i used a booster pedal before it, and it sound great
but as a standalone.. i don't know..
can you guys pls suggest some modifications? thx!

Hi awitee,

You could try to run off 12 volt.(more headroom)
But you have to watch the heater voltage.
If you connect 12 volts to 4 and 5 of the tube, you will be alright.
With the bass thing....you can change the input cap.
I believe a smaller cap --> less bass.
Also, you can try to remove the tone-circuit or make it switchable(gives a little more gain).

success with your valvecaster!
mods i made was, i paralleled the 1M resistor with 690k to get a lower resistance for more gain
i also changed the input cap to .022microfarads to lessen the bass
and then i changed the gain pot back to the 50k B from 1M A
and also i now run it at 12V
results... OH YEAH hahaha
so happy with the result, great overdriven sound!! i couldnt be more happier
sounds super great when i drive it with either my queen may booster or ts808 clone
super great tone
im not sure what to do with the "But you have to watch the heater voltage." coz im not really experienced with tubes hehe this is my first tym
but it's still working so i guess im fine hehe thx alot for the help and instructions on this thread!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on May 01, 2008, 09:07:53 AM
So, what is the expected gain of this circuit (at 12V) anyway? I'm planning to use this as a preamp for my power amp and I'm concerned that it may not provide enough gain to sufficiently drive the amp. I can adjust the gain of the power amp input stage but I'm not sure that will be enough if the gain from the preamp is too low. Keep in mind I'm not looking for crazy overdrive/distortion. This is going to be for blues so if the gain goes from clean to just starting to break up when cranked, it will be perfect. Of course, this assumes the distortion comes from the first stage overdriving the second, not both overdriving the power amp :)

Also, why would you reduce the input impedance if you're trying to get more gain? The lower the input impedance is the more input signal will be lost to ground. If anything, I would say to try 2M on the input resistor to increase the signal available to the first gain stage. Or am I missing something?
-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 02, 2008, 12:39:55 PM
Subcaster working!

All I did was remove C2, the 47nf cap across the supply rails and replace it with a different kinda 47nf cap. Weird. Hmmm, been bugging me for weeks!

So - I fired my Valvecaster into my Subcaster - WOW!!

It seems to me that the hassle of creating a 6.3 volt supply for the 6111 heater is a pain in the butt compared to powering a 12au7 heater at 12 volts. There really is no saving on space when you consider the extra circuitry required for the voltage regulator - and a heatsink on the LM317 too! There is a whole lot of heat generated by a 6111 in comparison to a 12au7. add that to the heat the LM317 gives out and you can warm the living room up nicely with a Subcaster!

My rule of thumb now will be to only use 6111's in pairs and run the heaters in series of 12 volts.

So - go ahead and build a Valvecaster. Or a dual Subcaster. Or a Pepper Shredder using two 6111's, like I'm doing next.

(Shit, I would do it this weekend but I have to write some music for Volvo!)

Just don't build a single 6111 Subcaster!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Pushtone on May 02, 2008, 03:09:34 PM

I had weak fizzy, farty tone with pathetic amount of gain with a $8.00 Yugoslavian tube.
Switched it with an $18.00 EH 12AU7 and I had plenty of gain and a nice over drive distortion.

After that...
I switched out the decoupling cap between stages to 0.0022uF to tune the bass where I like it with humbuckers.
Then I replaced the 1uf electro with a film cap.

I think it sounds great and I have plenty of gain. Yes a booster in front makes it sing!

Pics:
Top - link (http://www3.telus.net/david65/pedal-pics/valvecaster/vc-34-low.jpg)
Insides - link (http://www3.telus.net/david65/pedal-pics/valvecaster/vc-inside34.jpg)

Posted these in the pictures thread a while back.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: gaussmarkov on May 02, 2008, 06:26:32 PM
Pics:
Top - link (http://www3.telus.net/david65/pedal-pics/valvecaster/vc-34-low.jpg)
Insides - link (http://www3.telus.net/david65/pedal-pics/valvecaster/vc-inside34.jpg)

gorgeous dave!  :icon_cool:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DougH on May 05, 2008, 08:24:14 AM
Quote
I had weak fizzy, farty tone with pathetic amount of gain with a $8.00 Yugoslavian tube.
Switched it with an $18.00 EH 12AU7 and I had plenty of gain and a nice over drive distortion.

These comments lead me to believe that you need a way of adjusting the bias for different make/models of tubes. Aron included a bias adjustment in his Shake Tube for this purpose. You might look at that for ideas or there may be suggestions earlier in this thread (I haven't read the whole thing). I suspect you could get this to work with a lot of different tubes (with correct pinout) if you had a way of adjusting the bias.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: eddieod on May 05, 2008, 03:47:35 PM
Hi all,

I encounter similar problems in using different brands of tubes within the 12au7. When I put a JJ (former Tesla) 12au7 into this circuit (valvecaster) there's hardly any output at all! I have similar problems with other designs on low voltages also (like a pedal I developed called the "ts-tube"). Sometimes a tube really puts out a great amount of output and tone and sometimes it's just plain dead! EH's seems to be most consistent in working within such designs, but not always...I think it has something to do with the way the heater can generate sufficient electrons for the cathode to be able to work...Anyone with similar experiences? What can be done to have this solved? I personally don't believe you can get away with this just by changing the bias point for the reason in cause I mentioned earlier: if there's not enough dissipation from the cathode, there isn't anything to begin with...

What are your opinions on this?

Like to know.

Have fun,

Ed's Custom Shop
Edwin Thoen
Maarssen
The Netherlands
www.edscustomshop.com
Title: tubes
Post by: Renegadrian on May 05, 2008, 04:15:16 PM
Well, I own so many 12au7s, so i tried them all, and while their tonal nuances are all slightly different, they all work great...
I got NOS GE, Raytheon, RCA ecc. and a new EH as well...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DougH on May 06, 2008, 12:40:51 PM
Quote
These comments lead me to believe that you need a way of adjusting the bias for different make/models of tubes.

http://www.diystompboxes.com/smfforum/index.php?topic=63479.msg538894#msg538894 (http://www.diystompboxes.com/smfforum/index.php?topic=63479.msg538894#msg538894)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 07, 2008, 05:12:55 PM
Hi there,

Just finished a Subcaster with a 6111 of GE.
The amount of gain for overdrive isn't that much.
But that I don't mind, because I want to use it for Boosting Solo's.
Therefore the Subcaster works great.
I'll place some pictures, as soon as I have boxed it in.
But that can take a while :'(

But I changed the input powersupply filter from Dano a littlebit.
Because when you use Dano's scheme, you loose at least 1.5 volt.
Just do the maths (current for heater is 300mA and R1= 47 oHm leads to roughly 1.5 volt loss)
So I moved/replaced R1 with a coil of 1mH.
I made a change in Dano's scheme, Hope you don't mind Dano! ::)
Otherwise I remove your drawing!! ;)
(http://img232.imageshack.us/img232/1990/subcasterfinalyb4.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 07, 2008, 05:24:12 PM

But I changed the input powersupply filter from Dano a littlebit.
Because when you use Dano's scheme, you loose at least 1.5 volt.
Just do the maths (current for heater is 300mA and R1= 47 oHm leads to roughly 1.5 volt loss)
So I moved/replaced R1 with a coil of 1mH.


I removed both R1 and C2 From my Subcaster - it seems to work just fine.

Just finished a Subcaster with a 6111 of GE.
The amount of gain for overdrive isn't that much.
I found my Subcaster gives similar gain to my Valvecaster. My 6111 is a French CSF tube, I have a Penta 12au7 in my Valvecaster. I do have some dodgy unbranded 12au7's, which give less gain and a softer sound  - nice though. I have some Raytheon 6111's for my next build - so I'll see if they're different.

As someone said earlier in this thread - 'its all about the tubes!'
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: puretube on May 07, 2008, 07:05:43 PM
Hi there,

Just finished a Subcaster with a 6111 of GE.
The amount of gain for overdrive isn't that much.
But that I don't mind, because I want to use it for Boosting Solo's.
Therefore the Subcaster works great.
I'll place some pictures, as soon as I have boxed it in.
But that can take a while :'(

But I changed the input powersupply filter from Dano a littlebit.
Because when you use Dano's scheme, you loose at least 1.5 volt.
Just do the maths (current for heater is 300mA and R1= 47 oHm leads to roughly 1.5 volt loss)
So I moved/replaced R1 with a coil of 1mH.
I made a change in Dano's scheme, Hope you don't mind Dano! ::)
Otherwise I remove your drawing!! ;)


One milly is better than no Henry at all,
but if this Dano "subcaster" (http://www.beavisaudio.com/Projects/ValveCaster/Subcaster.gif) schemo
is the one you compare yours (http://img232.imageshack.us/img232/1990/subcasterfinalyb4.gif) with,
check out where in Dano`s the heater current is running through (R1, and causing a drop...), going where,

and which current is running through L1 in yours,
and will that ever effect the heater? 
 :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 08, 2008, 12:12:31 AM
One milly is better than no Henry at all,
but if this Dano "subcaster" (http://www.beavisaudio.com/Projects/ValveCaster/Subcaster.gif) schemo
is the one you compare yours (http://img232.imageshack.us/img232/1990/subcasterfinalyb4.gif) with,
check out where in Dano`s the heater current is running through (R1, and causing a drop...), going where,
The voltage drop is on B+, wich you don't want.
The coil hardly gives a drop on B+.
But you can leave R1 (and L1) out when you use a good powersupply just what frequencycentral wrote.

And which current is running through L1 in yours,
and will that ever effect the heater? 
 :icon_wink:
everything except for the heater current, causing hardly a voltage drop on B+
The heater current is going through the regulator so there will be hardly a Hum there.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on May 08, 2008, 01:55:26 PM
Has anyone tried this circuit with a 12U7? They're designed to run with a plate and heater voltage of +12V. I'm wondering if they will produce any better results than using the 12AU7 which wants +100V or so on the plate.

Oh, and they're cheap...

-Matt
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 08, 2008, 02:00:41 PM
Has anyone tried this circuit with a 12U7? They're designed to run with a plate and heater voltage of +12V. I'm wondering if they will produce any better results than using the 12AU7 which wants +100V or so on the plate.

Oh, and they're cheap...

-Matt

This is a long thread.....but if you check back I'm pretty sure someone mentioned using a 12u7 and getting a softer sound with less gain.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: emx on May 20, 2008, 01:47:48 PM
How well does this work on line-level stuff?  I'm looking to build something like this in stereo for synth use.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 24, 2008, 05:57:56 PM
Hi there,

I finally had some time to box my pepper shredder in.
I called it the INDIAN TWIN TUBE DISTORTION>
Only the knobs are missing.
The box i used was an old printer switch (one printer more computers).
There were some holes in the lower part, that I had to close.
Put some tolex over it, and the holes were gone!

I also placed a 6-way switch for the input caps.

So here are some pictures :

(http://img514.imageshack.us/img514/7312/indianfrontgz4.jpg)
(http://img514.imageshack.us/img514/9083/indiangutshy0.jpg)
(http://img514.imageshack.us/img514/605/zijfc8.jpg)

I'm very pleased with the overall look.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 24, 2008, 08:52:13 PM
Nice work...Want to listen to some clips!!! And maybe some detailed info about your pedal, the circuit, the components used, the PCB, etc...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 24, 2008, 09:08:15 PM
Excellent work Jimmy H. I'm currently working on another Valvecaster with the tube mounted in a similar way to yours.

The Pepper Shredder is on my list - I'll use 6111's - i've been able to confirm that two 6111 heaters in parallel will run on 12 volts.

Which input caps do you have available by that switch - and can you describe the variations?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 25, 2008, 08:00:06 AM
Nice work...Want to listen to some clips!!! And maybe some detailed info about your pedal, the circuit, the components used, the PCB, etc...

Hi Renegardian,

Thanks...
Most of it is discriped a few pages ago : http://www.diystompboxes.com/smfforum/index.php?topic=63479.420
PCB, layout (a page further) and the schemo of Tube Town.

The only things I added was a Fender-like tone stack.
(http://img236.imageshack.us/img236/8233/tswr6.jpg)
(http://img236.imageshack.us/img236/1126/tonestackum7.gif)

And the orange input selector:

(http://img236.imageshack.us/img236/3716/preamporangenw1.jpg)

These caps were soldered directly on the 6-way switch

It's prettymuch standerd stuff 0.5 watt resisters, filmcaps etc.
And not to forget 12U7 tubes.
Links to soundfiles were posted back then (only with more common 12au7 tubes).
It sounds very similar to mine.

Excellent work Jimmy H. I'm currently working on another Valvecaster with the tube mounted in a similar way to yours.

The Pepper Shredder is on my list - I'll use 6111's - I've been able to confirm that two 6111 heaters in parallel will run on 12 volts.

Which input caps do you have available by that switch - and can you describe the variations?



Thanks again frequencycentral ,

The switch is very usefull with different guitars.
It filters more or less bass-signals at the input.
I'm also thinking about to make the tonestack switchable.

And 12 volts for two 6111-tubes work great.
I'll like to hear from your 6111-pepper shredder!
Keep us posted!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 25, 2008, 02:52:20 PM
thx for the reply jimmy!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 25, 2008, 03:22:37 PM
thx for the reply jimmy!!!  :icon_wink:

You're welcome Renegardian :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on May 25, 2008, 05:19:00 PM


(http://img514.imageshack.us/img514/9083/indiangutshy0.jpg)


VERY nice job !!!!!  :) The blue led idea is killing !

(May I take the opportunity of this post to ask if anybody know were I can get some tube socket adapted for 6111 tubes ? Thanks!)


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 25, 2008, 05:34:26 PM
[quote author=Darkness, Darkness link=topic=63479.msg544368#msg544368 date=121175034

(May I take the opportunity of this post to ask if anybody know were I can get some tube socket adapted for 6111 tubes ? Thanks!)



[/quote]

Hi Darkness,

I used a 8-pin ic-socket, just like Dano had written before.
This works very well.
Just cut the leads and bent it a little.

This is wat Dano wrote:
<edit: also found a potentially great way to mount those flying lead wires: use an 8-pin DIP socket as seen here: http://www.geocities.com/koalavilla/images/audio/pencil_pre_10.jpg >
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on May 25, 2008, 05:46:53 PM

Thank Jimmy-H ! Good idea, very clever I must say. I'll try this. Maybe just check for a model where I can be sure the tubes won't move (when moving the stombox for example) 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 25, 2008, 06:20:30 PM
Maybe just check for a model where I can be sure the tubes won't move (when moving the stombox for example) 

6111 tubes are designed to be soldered (or welded) directly to the board. You could try this. I did this with my Subcaster.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 25, 2008, 06:44:13 PM
What about those...
http://www.scame.com/images/serie/mor001.jpg
or those used in audio amps...
http://www.quasarelectronics.com/images/3000/3047.jpg
The valve's wires could be hooked with one of the above, maybe...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 26, 2008, 06:56:17 AM
I'm currently woking on a LPB-1/Valvecaster pedal and I've come up with a neat way to mount the tube inside the enclosure:

(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0220.jpg)

I considered all sorts of other ways: bolting the tube socket to the side of the enclosure, mounting it using a bent bit of metal etc.

This way works really well. I used fibreglass perf, which is really tough, and drilled/filed a hole big enough for the socket. The socket is actually soldered to the board after using wire to secure it in place. The resulting board JUST fits the enclosure. The pot/circuit to the left is the LPB, the pot to the right is the Valvecaster volume.

I'll be using two stomp switches - one to use the LPB to boost, the other to bypass both circuits.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 26, 2008, 07:16:28 AM
Great pic, Rick...Just 2 Qs..

1) What kind and size of enclosure are you going to use?
2) LPB+Valvy=didn't try myself (but I'll do, as I have one LPB lying around...) - but IMO the Valvy is not treble screaming, and LPB is famous for being on the bass side...So how do they sound togheter? Aren't they too much on the bass side? Can this couple give some decent highs?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 26, 2008, 08:22:07 AM
I'm currently woking on a LPB-1/Valvecaster pedal and I've come up with a neat way to mount the tube inside the enclosure:

(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0220.jpg)

I considered all sorts of other ways: bolting the tube socket to the side of the enclosure, mounting it using a bent bit of metal etc.

This way works really well. I used fibreglass perf, which is really tough, and drilled/filed a hole big enough for the socket. The socket is actually soldered to the board after using wire to secure it in place. The resulting board JUST fits the enclosure. The pot/circuit to the left is the LPB, the pot to the right is the Valvecaster volume.

I'll be using two stomp switches - one to use the LPB to boost, the other to bypass both circuits.

Hi frequencycentral


Looks good!
It's funny, because my Subcaster looks almost the same.
Eeeeh we are on the same frequency isn't it!!

Only I made a PCB.
In this way you have very few wires.
I drilled a whole under the IC socket for the 6111 tube.
To mount a led the same way as my Indian pedal.
I'll see if I can place a picture tonight!

But I still have to box it in......in time.....
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 26, 2008, 08:30:13 AM
Great pic, Rick...Just 2 Qs..

1) What kind and size of enclosure are you going to use?
2) LPB+Valvy=didn't try myself (but I'll do, as I have one LPB lying around...) - but IMO the Valvy is not treble screaming, and LPB is famous for being on the bass side...So how do they sound togheter? Aren't they too much on the bass side? Can this couple give some decent highs?

(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0221.jpg)

The enclosure is a Hammond (Eddystone) 3907 (120x95x30) - from my local Maplin: http://www.maplin.co.uk/module.aspx?ModuleNo=43713&doy=26m5

As for the sound - it's what your ears enjoy! You have a Valvy and an LPB-2 (same as the LPB-1, EH just put it in a different box) - hook them up! I've been using my other Valvy with my LPB and really enjoy it - maybe there's a place for 'dark' in my guitar sound and on my pedalboard! I have a range of fuzz/overdrive/distortion to choose from now (I'm also working on the fuzz section of the Colorsound Fuzzwah, using vintage BC107's), it's nice to vary it a bit.


Hi frequencycentral

Looks good!
It's funny, because my Subcaster looks almost the same.
Only I made a PCB.
In this way you have very few wires.
I drilled a whole under the IC socket for the 6111 tube.
To mount a led the same way as my Indian pedal.
I'll see if I can place a picture tonight!

But I still have to box it in......in time.....

Thanks Jimmy. Great minds think alike......!

As for boxing stuff up - since I joined this forum my builds take longer - this is because you guys make some great looking pedals, and now it's not good enough for me to just get the electronics right - so I have to wait wait wait - for paint to dry, for decals to dry, for varnish to dry etc!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 26, 2008, 09:06:04 AM

You have a Valvy and an LPB-2 (same as the LPB-1, EH just put it in a different box) - hook them up!

I did, Rick...But my ears tell me I personally don't like the Valvy with the LPB - it sounds muddy and "fuzzy" to my ears, and there is no shine at all...I did my test with my toneless Valvy and the LPB2 trying with 2N5088 and BC108.

I really love to put a Tillman in front of my Valvies, it adds a little push and some shine...So it sounds more "complete" to my ears...It adds some highs that the Valvy alone hasn't got...

But hey that's the beauty of tastes, both yours and mine are ok, as long as it sounds good to the ears!!!  :icon_wink:
Isn't it?!?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 26, 2008, 09:25:28 AM
I did my test with my toneless Valvy and the LPB2 trying with 2N5088 and BC108.

I have BC547 in mine - too much hfe???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 26, 2008, 09:42:27 AM
I did my test with my toneless Valvy and the LPB2 trying with 2N5088 and BC108.

I have BC547 in mine - too much hfe???

Well, BC547 is supposed to be the ol' BC107 with more gain...
Anyway, I don't think it's a GAIN thing, but a tonal response of the circuit itself...
Too "bassy"...Not my cup of tea indeed...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 26, 2008, 05:56:30 PM
Hi frequencycentral ,

Here it is my: 6111-Subcaster.
You can see some resemblance with your design.
My idea was also a simple way of mounting the whole thing with the pots.
(http://img213.imageshack.us/img213/3078/6111subcasterwo8.jpg)

As for boxing stuff up - since I joined this forum my builds take longer - this is because you guys make some great looking pedals, and now it's not good enough for me to just get the electronics right - so I have to wait wait wait - for paint to dry, for decals to dry, for varnish to dry etc!

There your totally right!!!!


Thank Jimmy-H ! Good idea, very clever I must say. I'll try this. Maybe just check for a model where I can be sure the tubes won't move (when moving the stombox for example) 
As you can see darkness, the tube is mounted in a IC-socket.
It is sturdy enough when you move the stompbox !
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 26, 2008, 10:00:00 PM
Hi frequencycentral ,

Here it is my: 6111-Subcaster.
You can see some resemblance with your design.
My idea was also a simple way of mounting the whole thing with the pots.
(http://img213.imageshack.us/img213/3078/6111subcasterwo8.jpg)

Superb work Jimmy - it does look similar to mine! I tend to go for mounting the pots onto the circuit board whenever possible - cuts down off-board wiring and its an easy way to mount the board in the enclosure too! I did similar for my MXR Distortion+, which meant the board had to be only 18x8 holes - ultra compact - but also very pleasing. Also recently did an LPB for a friend this way, the board was 8x7 holes.

I love your blue LEDs too!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 28, 2008, 01:10:45 AM

Superb work Jimmy - it does look similar to mine! I tend to go for mounting the pots onto the circuit board whenever possible - cuts down off-board wiring and its an easy way to mount the board in the enclosure too! I did similar for my MXR Distortion+, which meant the board had to be only 18x8 holes - ultra compact - but also very pleasing. Also recently did an LPB for a friend this way, the board was 8x7 holes.
Thanks Frequencycentral,

I also did a few boards that way, it's also a bit of a challenge to fit the components in such a small space.

I love your blue LEDs too!

Thanks again, a great way of feeling blue!



Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 29, 2008, 08:07:11 PM
(http://img294.imageshack.us/img294/9443/290509xi6.th.jpg) (http://img294.imageshack.us/my.php?image=290509xi6.jpg)

Here is my third Valvy, I also posted it in the Pictures thread...

Again, it has some slight differences from the original circuit I layed out
(http://img245.imageshack.us/img245/3325/valvecasternotoneog3.th.jpg) (http://img245.imageshack.us/my.php?image=valvecasternotoneog3.jpg)

* I raised the R1 and R2 values - R1 = 2.2M | R2 = 390K
* This time I used a electr. cap for C3, as in the original Dano schem - a normal cap works too BTW
* I tried a bigger value for the GAIN pot - 250k - but it wasn't just right...I changed back to the original value...
* Again, NO useless tone control...And NO LED. Staight tube power.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sengo on May 29, 2008, 09:44:26 PM
Hello folks,

I just built my first Valvecaster, and it doesn't sound right, no where near as beautiful as the sound clips I've heard from other forum members. I was wondering if I should ask for help here or start a new thread?

Nick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 30, 2008, 02:18:56 AM
(http://img294.imageshack.us/img294/9443/290509xi6.th.jpg) (http://img294.imageshack.us/my.php?image=290509xi6.jpg)

Here is my third Valvy, I also posted it in the Pictures thread..

Looks Great Adriano!!!!!
I also have seen them on the picture thread.


But some of my pictures have dissapeared (again) .   :icon_evil:
Have some of you the same problem with ImageShack?  ???

So I post my Indian Twin-Tube Distortion again:

(http://img46.imageshack.us/img46/518/indiangutsus4.jpg)

(http://img46.imageshack.us/img46/2258/indianfrontop9.jpg)

(http://img46.imageshack.us/img46/7039/zijds0.jpg)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 30, 2008, 05:36:01 AM
Hello folks,

I just built my first Valvecaster, and it doesn't sound right, no where near as beautiful as the sound clips I've heard from other forum members. I was wondering if I should ask for help here or start a new thread?

Nick

I believe that's the right place...
All right, first tell us how did you build this:

Did you use my vero layout, or Dano's point to point or...
Tone or toneless...
9v or 12v...
Is the sound coming out correctly in bypassed mode...
Did you change some components or kept the original list...
Did  you double-triple check every connection...
Did you try with another tube and wall wart...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sengo on May 30, 2008, 11:44:17 AM
Quote
Did you use my vero layout, or Dano's point to point or...
Tone or toneless...
9v or 12v...
Is the sound coming out correctly in bypassed mode...
Did you change some components or kept the original list...
Did  you double-triple check every connection...
Did you try with another tube and wall wart...

I used Dano's point to point layout, with no tone control and no volume control (I was just trying it out, so I did not spend the time to soldier up a volume pot). It's running at 9V, and I've tried both a wall wart and a 9V battery, they both sounded quite similar except the wall wart added noise. I used all the original components, and I checked them numerous times to make sure they were right, and right now it is wired up with no bypass switch (effect always on). It actually works alright, but it sounds very gated, buzzy, and weak, similar to a very mis biased fuzz face. When I boost the input signal I get much more overdrive (obviously), but its not very nice sounding, very buzzy.
I only have two 12AU7 tubes, and they are both EH, one is normal, and the other is "high gain". Could the tube brand make that much of an impact on the tone? After I already ordered the tubes I found out that many of the builders were displeased with EH tubes, but they didn't sound THIS bad did they?     
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 30, 2008, 11:52:00 AM
sengo - check the battery voltage - my battery Valvecaster starts to sound bad once the battery goes down below 8 volts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 30, 2008, 12:33:03 PM
Nick, the wall wart noise is easily resolved with the voltage regulator you can read in this very same thread...
Basically its just a 100uF el. filter cap and a 7809 or 7812
Else, I dunno what to tell you...recheck the tube pins' number...
As for the tubes, I have one new EH 12AU7 bought from Banzai - No, they don't sound so bad, you can get better tubes, but the one I got sounds good, so it stays...So the tube is not to blame...
Different brands have different tone nuances, but they all work as long as they are the same type...

Maybe post some pics of your attempt...We can check it better...

EDIT - try it at 12v too.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DougH on May 30, 2008, 12:36:26 PM

So I post my Indian Twin-Tube Distortion again:


I love that Indian logo. :icon_wink:

Nice work!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on May 30, 2008, 01:24:42 PM
Hello folks,

I just built my first Valvecaster, and it doesn't sound right, no where near as beautiful as the sound clips I've heard from other forum members. I was wondering if I should ask for help here or start a new thread?

Nick

In addition to Renegadrian's suggestions, what kind of sound are you getting?  If it's sputtering "farting" kind of sound maybe the ground wire to the jacks aren't connected (I had that happen when I was prototyping mine).  Maybe a picture can help.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on May 30, 2008, 03:25:38 PM
Builded the valvecaster. Great stompbox. No hum - a real quit one.
Gives me the Keith Richards sound.
Karsten

(http://www.felicienne.com/extra/valvecaster.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 30, 2008, 03:28:12 PM
Builded the valvecaster. Great stompbox. No hum - a real quit one.
Gives me the Keith Richards sound.
Karsten

(http://www.felicienne.com/extra/valvecaster.jpg)

Excellent build! The tube protector reminds me of the TubeTown Pepper Shredder!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Pushtone on May 30, 2008, 03:35:04 PM

The tube protector is brilliant.
A couple of standoffs and washers.
Love it.

Dave S.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 30, 2008, 04:06:47 PM
Really nice build!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on May 30, 2008, 05:54:10 PM
yep,
Inspired by tube town  ;D.
M24 steel washer.

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on May 31, 2008, 02:41:40 AM

I love that Indian logo. :icon_wink:

Nice work!!

Thanks DougH !
I also like it a lot.
Gives it a bit vintage look !
But strange, the lost pictures have returned again........strange Image Shack!!

yep,
Inspired by tube town  ;D.
M24 steel washer.

Karsten

Karsten a very clever solution ;) .
I've seen such a tube cage at Banzai. http://www.banzai-effects.de/Gold-tube-cage-pr-20588.html

But i found them to expensive.
The way you did it saves a lot of money  :icon_smile: !!!
Again, a beautiful design...your box
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: LMJS on May 31, 2008, 07:54:29 AM
Iorr, any chance of an interior "gut" shot pic?
Please!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: iorr on May 31, 2008, 09:15:15 AM
Sure  :icon_wink: Little bit of chaos in there....

(http://www.felicienne.com/extra/valveinside.jpg)

Karsten
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on May 31, 2008, 02:04:57 PM


Thank Jimmy-H ! Good idea, very clever I must say. I'll try this. Maybe just check for a model where I can be sure the tubes won't move (when moving the stombox for example) 
As you can see darkness, the tube is mounted in a IC-socket.
It is sturdy enough when you move the stompbox !


Thanks !! I'll use this method for sure ! :) I have received the tubes but still waiting for the LM317 .... :(
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on May 31, 2008, 02:12:36 PM
Builded the valvecaster. Great stompbox. No hum - a real quit one.
Gives me the Keith Richards sound.
Karsten

(http://www.felicienne.com/extra/valvecaster.jpg)

Really too cool looking !!!!!   great job !
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: LMJS on May 31, 2008, 03:34:10 PM
Iorr, thanks for the inside shot.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on June 01, 2008, 02:52:31 AM
Hello folks,

I just built my first Valvecaster, and it doesn't sound right, no where near as beautiful as the sound clips I've heard from other forum members. I was wondering if I should ask for help here or start a new thread?

Nick

In addition to Renegadrian's suggestions, what kind of sound are you getting?  If it's sputtering "farting" kind of sound maybe the ground wire to the jacks aren't connected (I had that happen when I was prototyping mine).  Maybe a picture can help.

Why don't you post some sound clips ? It's probably easier to hear what's wrong than to see it in this case - since the circuit is working. Try different tubes. I've had great success using 5751's on my last few builds.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 01, 2008, 04:22:44 AM
I also tried some tubes labelled 5963 - they work.
but as you can read they're part of the same family.

http://www.nj7p.org/Tube4.php?tube=5963
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on June 01, 2008, 05:58:17 AM
All nine pin double triodes "work" in this circuit. 5751's are low to medium gain and like the mentioned 5963 is a very good substitute for something like a 12AU7. I also tried some NOS GE 12AV7's and they are okay, although IMO not as nice and creamy as the 5751.

Has anyone tried anything from JJ in this thing lately ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on June 01, 2008, 06:13:59 AM
Has anyone tried anything from JJ in this thing lately ?

Yes, JJ 12AU7. Compared to a RCA 5751 it was brighter, "brittle" would be a word to describe the difference. I think the JJ would be better for a live situation where the pedal was being used as a lead boost. The RCA sounds nicer when being hit by a boosted signal.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 01, 2008, 01:53:03 PM
Already out this in the 'Pictures!' thread but what the hey!

Valvecaster with stompable LPB boost:

(http://i210.photobucket.com/albums/bb292/frequencycentral/moto_0258.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 01, 2008, 02:58:40 PM
thanks for sharing, Rick!!!
I love to see other people's work, expecially on the Valvy...
Altough it's the same f***ing circuit wit the lowest components list, every pedal looks different from the others...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 01, 2008, 03:20:04 PM
Hi Rick,

Sure looks great!!
The Tube is invisible, but well protected.
Very practical on the road.
Really nice build.
Looking forward to your next!

A hell of a thread you started here Dano!  :D
And it seems not to end yet :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 01, 2008, 03:26:59 PM
thanks for sharing, Rick!!!
I love to see other people's work, expecially on the Valvy...
Altough it's the same f***ing circuit wit the lowest components list, every pedal looks different from the others...

Thanks Adriano - yeah simple circuit - but it was wiring the two 3pdts that was the mindbender here. I made the bypass switch bypass both circuits, the boost switch just cuts out the LPB. Took a while to get my head around how to do that!

Hi Rick,

Sure looks great!!
The Tube is invisible, but well protected.
Very practical on the road.
Really nice build.
Looking forward to your next!

A hell of a thread you started here Dano!  :D
And it seems not to end yet :icon_wink:

Thanks Jimmy. Well protected - yes! My first VC was for home use - this one is for gigging with.

As for other builds - I finished three other enclosures yesterday, all the electronics done too - I just need to 'pot' them up - so it should be a bumper week for me in the 'Pictures!' thread.

And yes - one hell of a thread - its this thread and Dano's site which got me into the forum in the first place.

Thanks again Dano!

Rick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on June 01, 2008, 07:19:55 PM
  Hi Rick, question for you. I'm curious how hot your pedal gets with the LM317 and the tube inside the enclosure? I'm wondering if I need to drill vent holes before I paint.
  Thanks, Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 01, 2008, 07:39:26 PM
  Hi Rick, question for you. I'm curious how hot your pedal gets with the LM317 and the tube inside the enclosure? I'm wondering if I need to drill vent holes before I paint.
  Thanks, Jered

Hi Jered,

There is no LM317 inside - this Valvecaster runs on 12 volts, including the heater.

Maybe its the Subcaster that you are thinking of that needs the LM317 for its 6.3 volt heater?

As for heat off the tube - I only finished the pedal today, so it hasn't been plugged in for long. I'll be using it at band practice on Wednesday so I'll report back. I did consider vents - I may still have to drill them!

My other Valvecaster is 9 volt battery powered - the tube gets warm but not hot. I don't know how much differance it will make being powered at 12 volts from a wallwart.

I can tell you this: I built a little amp recently, using a Subcaster as a preamp into a LM386 based amp, I'll be boxing it up this week. The 6111 submini tubes get much hotter than 12au7 tubes, and the LM317 does get seriously hot - even with a heatsink. The enclosure for this project is vented.

Rick


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on June 01, 2008, 10:20:35 PM
  Thanks Rick, I wasn't sure what voltage you were running it at and needed the volt reg or not, that's why I asked. Please do post your results after your rehersal, I'll hold off on the vent holes until then.
  Thanks, Jered
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sengo on June 02, 2008, 07:19:14 PM
Hi again,

Sorry I have taken so long to respond about my Valvecaster.

I took some voltages, ans was wondering if anyone could compare theirs to mine? To me it just sounds really poorly biased. I also found out my 9V 500 mA power supply actually runs around 12.6 Volts when not plugged into the jack on my Valvecaster, it is an EH power supply. when the jack and take a reading across the positive terminal and ground I get a reading of 11.05 Volts, but I have gotten readings as low as 10.9V. Here are my voltages:

Pin 1: 7.63V
Pin 2: 0.00V
Pin 3: 0.72V
Pin 4: 0.00V
Pin 5: 10.99V
Pin 6: 4.46V 
Pin 7: 0.37V
Pin 8: 0.00V
Pin 9: 5.52V

A lot of these voltages seem to fluctuate slightly while taking them. I don't know if that will help diagnose the problem. I'll try to get a picture up later perhaps, but I don't know how helpful that will be, right now my project sort of looks like an octopus.

Nick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Pushtone on June 03, 2008, 06:01:52 PM

A few weeks ago I reported that a brand new YUGO tube (12AU7) that I paid $8.00 for sounded terible in the Valvecaster. Farty, sputtery, week, no gain.

I swapped it for the EH tube thats been serving in my Firefly amp. Ah, tonal bliss with the Valvecaster and EH tube.

The Yugo tube got put in place of the EH in the Firefly amp where I could not tell the difference between tube. They sound the same in the Firefly.

Three weeks later the Yugo has about 6 - 8 hours of use in the firefly amp.
I pull it out of the amp and into the Valvecaster.  Gee, it sounds very good now. WTF.

Did it get burned in from the high voltage in the Firefly?  Why does it sound good now?

Before the difference between the Yugo and the EH has huge. Now there is  a "just noticeable difference" between the two.
The EH is still better, but only slightly.

One side note to this history....
The Yugo flashes a bright white light from inside the tube near the base when the Firefly is powered on.
The EH has never done this.

Is it important to burn in a tube?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 03, 2008, 06:37:37 PM
sengo, I'm not a multimeter guy, I have a rawer approach (Wire it - it works - yell in glory!!!  :icon_twisted: - it doesn't work - yell in rage!!!  :icon_evil: )
So I cannot be of any help with those voltages...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 03, 2008, 08:01:12 PM
sengo - I'm busy for the next few days but will post some voltages to compare on thursday - unless someone else gets to you first.

Rick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: brett on June 03, 2008, 11:03:46 PM
Hi
RE: Yugo tube playing up and "Why does it sound good now?"

Wild guess - A couple of time I've had new tubes that make poor connections into sockets.  Once they make contact and get hot and get going, they are OK.  Given the low voltages here and high voltages in the firefly, it might have been the plate pins that had a film of corrosion on them or were not making contact.
cheers

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 04, 2008, 08:57:07 PM
  Thanks Rick, I wasn't sure what voltage you were running it at and needed the volt reg or not, that's why I asked. Please do post your results after your rehersal, I'll hold off on the vent holes until then.
  Thanks, Jered

I ran my red Valvecaster/LPB for 3 hours tonight at rehearsal. Immediatly after unplugging it I opened it up and 'kissed' the 12au7 - lips being very sensitive to heat. It was warm but not hot. The enclosure was colder but a tiny bit warm. My 500ma regulated DC adapter was way hotter. Thats good enough for me - no vents needed. I was running it at 12 volts.

Also, the way I configured the two 3pdt was excellent. The 'bypass' 3pdt cuts of both effects for true bypass, the 'boost' 3pdt brings the LPB in and out. Real Easy to go from clean to rhythm (VC) to lead (LPB > VC).

The other guitarist in my band wants one!

I kissed my tube and it felt good.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 04, 2008, 09:10:44 PM
YOU PERVERT!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 05, 2008, 07:13:18 AM
[
I ran my red Valvecaster/LPB for 3 hours tonight at rehearsal. Immediatly after unplugging it I opened it up and 'kissed' the 12au7 - lips being very sensitive to heat. It was warm but not hot. The enclosure was colder but a tiny bit warm. My 500ma regulated DC adapter was way hotter. Thats good enough for me - no vents needed. I was running it at 12 volts.

Also, the way I configured the two 3pdt was excellent. The 'bypass' 3pdt cuts of both effects for true bypass, the 'boost' 3pdt brings the LPB in and out. Real Easy to go from clean to rhythm (VC) to lead (LPB > VC).

The other guitarist in my band wants one!

I kissed my tube and it felt good.


MMMMMMMMMMMMM........that's new Tube kissing in the Stompbox society!!!! :icon_rolleyes:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 05, 2008, 01:10:26 PM
YOU PERVERT!!!  :icon_wink:
[
I ran my red Valvecaster/LPB for 3 hours tonight at rehearsal. Immediatly after unplugging it I opened it up and 'kissed' the 12au7 - lips being very sensitive to heat. It was warm but not hot. The enclosure was colder but a tiny bit warm. My 500ma regulated DC adapter was way hotter. Thats good enough for me - no vents needed. I was running it at 12 volts.

Also, the way I configured the two 3pdt was excellent. The 'bypass' 3pdt cuts of both effects for true bypass, the 'boost' 3pdt brings the LPB in and out. Real Easy to go from clean to rhythm (VC) to lead (LPB > VC).

The other guitarist in my band wants one!

I kissed my tube and it felt good.


MMMMMMMMMMMMM........that's new Tube kissing in the Stompbox society!!!! :icon_rolleyes:
I am not ashamed. It felt right at the time. I would definately do it again if the occasion arose.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 05, 2008, 02:00:54 PM
I wrote this on one of the Sparkle Boost topic, in reply to an Andy question about the SB before a Valvy, I think it has to be reported here too...

I run the SB with the 2n5457 in, then my toneless Valvy with vol and gain set at something less than the max.
The SB is a good companion, expecially on solos - high notes are well defined even at its max gain.
You may want to tweak the amp highs, as to get the best results on the E or A string palm muted riffs...
That said both at SB min and max gain.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 05, 2008, 04:43:34 PM
Hi again,

Sorry I have taken so long to respond about my Valvecaster.

I took some voltages, ans was wondering if anyone could compare theirs to mine? To me it just sounds really poorly biased. I also found out my 9V 500 mA power supply actually runs around 12.6 Volts when not plugged into the jack on my Valvecaster, it is an EH power supply. when the jack and take a reading across the positive terminal and ground I get a reading of 11.05 Volts, but I have gotten readings as low as 10.9V. Here are my voltages:

Pin 1: 7.63V
Pin 2: 0.00V
Pin 3: 0.72V
Pin 4: 0.00V
Pin 5: 10.99V
Pin 6: 4.46V 
Pin 7: 0.37V
Pin 8: 0.00V
Pin 9: 5.52V

A lot of these voltages seem to fluctuate slightly while taking them. I don't know if that will help diagnose the problem. I'll try to get a picture up later perhaps, but I don't know how helpful that will be, right now my project sort of looks like an octopus.

Nick

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

DC power in is reading 11.99v.

Gain at maximum.

Edit: My gain pot is 100K not 50K.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sengo on June 06, 2008, 01:37:38 AM
Quote
Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

DC power in is reading 11.99v.

Gain at maximum.

Edit: My gain pot is 100K not 50K.

Thank you very much Rick, I really appreciate it! It looks like I may have messed up the resistors going to pins 1 and six, seen as my voltages are nearly opposite yours. I've checked them numerous times, but I've made mistakes like that before...

Thanks again,

Nick
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 06, 2008, 05:34:44 AM
Else you could try the vero version if that helps...It's more than verified  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 06, 2008, 01:11:36 PM
I also tried some tubes labelled 5963 - they work.
but as you can read they're part of the same family.

http://www.nj7p.org/Tube4.php?tube=5963

I just tried this Tube in my Pepper Shredder.
There's not much difference in sound compared to the 12U7 tubes I used.
The tube was a 5963 made by Beckman.
I never heard of this label.
But probably it's a relabeled GE tube (according to google....).
And one good thing about this Tube, is the price.
I payed 4 Euro for one tube, that's  cheap (in Holland).

The only difference between a 5963 and a 12AU7 is the maximum plate voltage.
250 V for 5963 And 330 V for a 12AU7.
But eeh... we are running from 12 volts here!  ;)

So Adriano it's good that you mentioned this Tube.

And I didn't kissed the Tube ..........Yet ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 06, 2008, 01:23:39 PM
And I didn't kissed the Tube ..........Yet ;D

Maybe 5963 tubes are better kissers than 12au7's? :-*
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 06, 2008, 01:48:47 PM
Maybe 5963 tubes are better kissers than 12au7's? :-*

Let's see  :-*  :-*  :-*..........Yeah definitely!!!!


 :)  :D :icon_biggrin:  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on June 18, 2008, 02:49:08 PM
Hi everybody,

Has anyone tried some 6112 tubes ? I can't get any sound of it  :( Maybe the 6112 does not work at all with low voltage ???? After all tubes are designed for high voltage...  :-\

- I've build a Voltage regulator for the heater -> OK :  6,3v, the tube lights up

- At begining I was trying to replace the JFET in the first stage of a working distorsion breadboard project just to test, and as is what not working I build on another breadborad the first stage of the valvecaster without more success I must say. Only difference : I run it at 24V (so I replaced the 220K  by a 1M pot to be able to set the bias...)

I've check, double check, and check again pins layout but it is good. (Even tried to invert anod/cathod just to be sure...) I don't get any sound and when trying to bias the tube at half supply voltage, there is almost no drop voltage on the bias pot (24-> 22V with a 1Meg pot set at full), meaning there is almost no current flow through the tube I would say  ???

What's you opinion ? Should I forget using these tubes ?

Thanks
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aab0mb on June 18, 2008, 03:12:45 PM
Hi everybody,

Has anyone tried some 6112 tubes ? I can't get any sound of it  :( Maybe the 6112 does not work at all with low voltage ???? After all tubes are designed for high voltage...  :-\

- I've build a Voltage regulator for the heater -> OK :  6,3v, the tube lights up

- At begining I was trying to replace the JFET in the first stage of a working distorsion breadboard project just to test, and as is what not working I build on another breadborad the first stage of the valvecaster without more success I must say. Only difference : I run it at 24V (so I replaced the 220K  by a 1M pot to be able to set the bias...)

I've check, double check, and check again pins layout but it is good. (Even tried to invert anod/cathod just to be sure...) I don't get any sound and when trying to bias the tube at half supply voltage, there is almost no drop voltage on the bias pot (24-> 22V with a 1Meg pot set at full), meaning there is almost no current flow through the tube I would say  ???

What's you opinion ? Should I forget using these tubes ?

Thanks

Maybe try a different tube.  I just built this little circuit and had a similar problem of no/low output w/ a 12at7.  I popped in a standard 12ax7 and it fired right up.  Not the best sound ever w/ a 12ax7 but at least it works.  If you can try different tubes first.  They all sound different.  Also, what kind of wallwart adapter are you using?  My OneSpot adapter works great but the other unregulated 9v and 12v that i had either didn't work or sounded like it was broken.  Good power supply is a MUST for this circuit IMHO.  Good luck w/ your project.

Aaron
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on June 18, 2008, 03:58:13 PM

Maybe try a different tube.  I just built this little circuit and had a similar problem of no/low output w/ a 12at7.  I popped in a standard 12ax7 and it fired right up.  Not the best sound ever w/ a 12ax7 but at least it works.  If you can try different tubes first.  They all sound different.  Also, what kind of wallwart adapter are you using?  My OneSpot adapter works great but the other unregulated 9v and 12v that i had either didn't work or sounded like it was broken.  Good power supply is a MUST for this circuit IMHO.  Good luck w/ your project.

Aaron

Thanks Aaron, I will try the spare tubes on tomorrow and a 12AX7 to check the circuit if it does not work better.

Concerning the power supply, I use a power supply for electronic labs (?? not sure how to say it in english ?? ? sorry  :icon_redface:)  It allows to get up to 30V/3A. I set it on 24V and the current limitation status is OK. I've also checked voltage of heater and circuit when everything is powered up and it was OK

let's try this on tomorrow so...  :)

Fab
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 19, 2008, 09:34:58 AM
Hi everybody,

Has anyone tried some 6112 tubes ? I can't get any sound of it  :( Maybe the 6112 does not work at all with low voltage ???? After all tubes are designed for high voltage...  :-\

- I've build a Voltage regulator for the heater -> OK :  6,3v, the tube lights up

- At beginning I was trying to replace the JFET in the first stage of a working distorsion breadboard project just to test, and as is what not working I build on another breadboard the first stage of the valvecaster without more success I must say. Only difference : I run it at 24V (so I replaced the 220K  by a 1M pot to be able to set the bias...)

I've check, double check, and check again pins layout but it is good. (Even tried to invert anode/cathod just to be sure...) I don't get any sound and when trying to bias the tube at half supply voltage, there is almost no drop voltage on the bias pot (24-> 22V with a 1Meg pot set at full), meaning there is almost no current flow through the tube I would say  ???

What's you opinion ? Should I forget using these tubes ?

Thanks

Hi Darkness,

On page three there was this reply from Jered:

Dano, I forgot to add, I tried 6112 and 6021 tubes and the sounded horrible. That's all.
  Jered

So there most be comming some sound out of your tube, even when it sounds like sh*T !!!
I think with 24 volts this tube will sound great.
There has to be something wrong with your build.
Keep in mind that jered only used 9 volts!

I hope that you will find what is wrong!  :-\
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on June 19, 2008, 10:17:09 AM
Hi Darkness,

On page three there was this reply from Jered:

Dano, I forgot to add, I tried 6112 and 6021 tubes and the sounded horrible. That's all.
  Jered

So there most be comming some sound out of your tube, even when it sounds like sh*T !!!
I think with 24 volts this tube will sound great.
There has to be something wrong with your build.
Keep in mind that jered only used 9 volts!

I hope that you will find what is wrong!  :-\

Hi Jimmy-H

I was thinking also that with 24 V it should be better...

I tried this morning another 6112 tube without more success. Haven't tried yet some 6021... But I tried a 12AX7 as suggested by Aaron and it works ! So my breadboard project is right  :) With half a 12AX7  I managed to make a booster that sounds great !!! Funny as I was thinking it would sound crap if it would sounds.... So I am playing around with a 12AX7 (JJ Electronics). Even funnier....I wasn't using this tube a lot because I thought it was not very good sounding in my Emery Sound amp  :D I will try other 12AX7 just to check....  Maybe I will continue my project with 12AX7 ?

I'll keep you posted of my results  ;)

Thanks !
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 19, 2008, 01:41:28 PM
Sure do, any entry is welcome!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 23, 2008, 03:33:25 PM
I added a new VERO version for the double valvy - it should work - Please check it out!!!
In the LAYOUT GALLERY search for TWINCASTER.

PS actually it's 2 layout, with and without the R1 at the beginning at the second stage. Someone said it's better to add that res...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on June 23, 2008, 03:34:31 PM
Hi everybody,

Today, I've played with 12AX7...well more in a plexi preamp way than the valvecaster  :icon_redface: but I am quite happy with the results  :) even if it remains lots of tweaking and tests to try ! Once I've got something well advanced i'll create a thread to share with you without hijacking this thread  :P And i will for sure have some question for you   :icon_wink:

Anyway just to say it also works great with some 12AX7 tubes : OK for a JJ/Tesla, OK for and EH but it does not work good with a Tung Sol (Breadboard powered at 24V)

This thread is just a killing idea !!!!! Thanks dano12  :)

To be continuated  ;)



Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on June 23, 2008, 04:41:56 PM
from Bugera (http://www.bugera-amps.com/index.cfm), the guru of tone:
scroll down to 12ax7Q valves (http://www.bugera-amps.com/_01/tubePage.cfm)!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 23, 2008, 04:55:16 PM
...Once I've got something well advanced i'll create a thread to share with you without hijacking this thread  :P And i will for sure have some question for you   :icon_wink:

Well, I believe our admin should change the title of this topic, I think nobody in this forum runs valves from a battery!!!  :icon_eek:
So it has turned into what we'd call "LOW VOLTAGE TUBE CIRCUITS".
Said that, your creations are more than welocmed in this very topic!!!

HINT, HINT: please, change that topic title!!!  :-[
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on June 24, 2008, 07:01:32 AM
Allright, decided to biuld this thing, (valvecaster) but since this thread is 30 pages long Im going to need some clarifications. (I did however read through it)

1. is there a good schematic for this thing including switches and whatnot? It seems to me that everyone is building different versions - im confused.
2. Is 12 V the power you want?
3. I was thinking of adding a switch for tube heating so that it can be kicked in without any delays - necessary?

It would be great if someone could explain and summarize this whole monsterthread a bit. (A huge FAQ for this project would be great for noobs like me)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 24, 2008, 12:13:48 PM
Allright, decided to build this thing, (valvecaster) but since this thread is 30 pages long I'm going to need some clarifications. (I did however read through it)

1. is there a good schematic for this thing including switches and whatnot? It seems to me that everyone is building different versions - I'm confused.
2. Is 12 V the power you want?
3. I was thinking of adding a switch for tube heating so that it can be kicked in without any delays - necessary?

It would be great if someone could explain and summarize this whole monsterthread a bit. (A huge FAQ for this project would be great for noobs like me)


Hi AKA_BASSE

1. Just build the original one on page 1.
   You can tweak it from there if you want.
    For instance if it's to bassy, make C1 smaller (20nF or 10nF).
    You can also make the tone control switchable. (switch between C4 and the connection of C3-VR3).
    If you like it without the tone control, You can leave it out.
2.Yep!
3.No, you don't need that.
  when you power it up, the tube get it's power also.
  the circuit always get it's current.
  the only thing that gets bypassed is the signal.(this is with every stompbox)

I hope that this is helpfull!!  ;)

Success with your build and keep us posted!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 24, 2008, 12:46:00 PM
Allright, decided to biuld this thing, (valvecaster) but since this thread is 30 pages long Im going to need some clarifications. (I did however read through it)

1. is there a good schematic for this thing including switches and whatnot? It seems to me that everyone is building different versions - im confused.
2. Is 12 V the power you want?
3. I was thinking of adding a switch for tube heating so that it can be kicked in without any delays - necessary?

It would be great if someone could explain and summarize this whole monsterthread a bit. (A huge FAQ for this project would be great for noobs like me)


A couple of weeks ago I trawled this thread and pasted various mod ideas into a Word doc, here's what I saved:

"I note that the original schematic and layout specify that the triode at pins 1-3 be used for the voltage gain stage, and 6-8 for the follower.

This isn't usually the best way to do it with a 12A*7.  With battery power or regulated DC going through the heaters, it doesn't matter which triode you use in which position, but if you're using AC or less-than-pristine DC, the triode at pins 6-8 will be quieter, due to the location of the heater pins on the tube.  (You can find mention of this in the data sheets on many 12A*7 series tubes.)



I lower the coupling cap between stages for less bass.



For lowering bass, you could try lowering the value of either the input cap, or the coupling cap between the two tube stages.



I am bypassing the Valvecaster gain pot with a 2.2nf cap. This helps maintain some brightness when the VC gain is turned down. For the input cap on the Valvecaster I am using a combination of caps to give me 2.7nf. This helps tighten up the bottom end.



To tame the gain I would lower R2 and R3. 220k and 100k seem pretty high for a low voltage circuit. Even in a regular high voltage amp the normal value is just 100k. So maybe cut them in half.



if you bring down that 220k to 100k it will def lower the gain a bit.  I built mine with both plate r's at 100k.



A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot.



Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain.



guitarx: replace the 100k resistor with 47k. Replace the 220k resistor with 100k.
Beautiful cleans   

To fellow Valvecaster experimenters -- I've currently got this circuit on a breadboard, switching out everything and I have some items of interest to report, especially for those looking for more gain.

The nicest clean sound I've found so far, is with the following mods:
R2 = 100k
R3 = 47k
C1 = 0.1uf
Remove C4 and VR2



Finally received that 7812 - mounted with the 100uF filter cap on the dc jack - hiss is just a memory... 
put a 100uF cap across the DC jack (positive leg to positive rail, neg. leg to neg. rail), then, instead of connecting the positive rail directly to the circuit, connect it to the regulator's pin1, ground to pin2, and the circuit to pin3. Then screw it on the enclosure. It is a 7812
."

I take no credit - its other peoples ideas - I just pulled it together for easy reference.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 24, 2008, 01:58:52 PM
1. is there a good schematic for this thing including switches and whatnot? It seems to me that everyone is building different versions - im confused.
2. Is 12 V the power you want?
3. I was thinking of adding a switch for tube heating so that it can be kicked in without any delays - necessary?

It would be great if someone could explain and summarize this whole monsterthread a bit. (A huge FAQ for this project would be great for noobs like me)

1. Go to the Layout Gallery and search for VALVECASTER - you'll find my verified vero layouts. Both Tone or Toneless.
Those layouts include jacks, power, switch, so you just cannot fail...
2. Yes
3. no need for that

A FAQ, you say...Well, that could be done...But I just can't figure out what to write about it!!! Maybe we could work at it togheter - you ask, we reply, so we can write down all the Qs' and the As'...
Hope that helps...



PS I'm building my 4th Valvy, a local bass player asked me to build it for him...And the graphics on this one are gonna kick serious a$$!!! I'll post it in some days...



PS Please give a look at my TWINCASTER layouts in the gallery - they should be correct, but hey I need your comments...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on June 24, 2008, 04:47:33 PM
Wow thanks alot guys!!

Jimmy -h - Great answers, made everything much clearer

frequencycentral - Wonderful list of tweaks, this is going to save me lots of time (not having to read through the thread all the time) and many others will probably find it useful

Renegadrian - Great layout, will probably follow that one. Can you get the sound of the "no tone" version with the "tone" version? What difference does it make to leave tone out? If Im going to use with both singlecoil and humbucker guitars wouldnt it be smart to leave it in there?

And if I understood correctly the effect will kick in instanly when you stomp it unlike, say, my amp which takes 10 sec before sound?

 Thats all the questions I had for now (likely many to come)
once again, thank you all very much!!

edit: also, what kind of caps and resistors should I use?
Title: VALVECASTER
Post by: Renegadrian on June 24, 2008, 08:01:21 PM
Renegadrian - Great layout, will probably follow that one. Can you get the sound of the "no tone" version with the "tone" version? What difference does it make to leave tone out? If Im going to use with both singlecoil and humbucker guitars wouldnt it be smart to leave it in there?
Well, the valvy is not so bright, so I had the tone always on 10 - else it will cut off all the highs and just won't cut thru...
Basically you have 2 ways
1. build it with the tone pot - it's very easy to get it out of the circuit if you'll find it useless as it was for me
2. Just go for the toneless version and get all the tone the valve can give...
I have several guitars, both SC and HB equipped, and no, I don't think the tone control is a must...
I use it with my bass too...

And if I understood correctly the effect will kick in instanly when you stomp it unlike, say, my amp which takes 10 sec before sound?
yes the tube will be always powered, as you can tell by the light of the tube itself

what kind of caps and resistors should I use?
standard components are used in this simple circuit.

Oh, before I forget...It was written several times that in order to avoid any hiss/noise, you need a good regulated wall wart, or use a 7812 voltage regulator and a filter cap on the DC jack. That is a must in my valvies...
Title: Re: VALVECASTER
Post by: Darkness, Darkness on June 24, 2008, 08:14:28 PM
Renegadrian - Great layout, will probably follow that one. Can you get the sound of the "no tone" version with the "tone" version? What difference does it make to leave tone out? If Im going to use with both singlecoil and humbucker guitars wouldnt it be smart to leave it in there?
Well, the valvy is not so bright, so I had the tone always on 10 - else it will cut off all the highs and just won't cut thru...
Basically you have 2 ways
1. build it with the tone pot - it's very easy to get it out of the circuit if you'll find it useless as it was for me
2. Just go for the toneless version and get all the tone the valve can give...
I have several guitars, both SC and HB equipped, and no, I don't think the tone control is a must...
I use it with my bass too...

There is also the possibility to use a pot with integrated turn-on-switch. I've got one in my emery sound amp, great feature  :)
Title: VALVECASTER
Post by: Renegadrian on June 24, 2008, 08:37:43 PM
Well, almost everything is possible, but I believe it would be just too much...I think you won't regret the absence of the tone pot...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: JOHNO on June 25, 2008, 02:44:05 AM
Well ive been messing around with this circuit today and while its supposed to run at 9 or 12 volts and it sounded ok at those voltages I just thought it was a waste. So I whipped up dano's voltage regulator using the LM317T and used a 5k trim pot because thats all i had on hand. Hooked it up to my bench top power supply and cranked it up to 20vdc.
Set the heaters to about 9v just to get the tube cooking a bit and it sounds pretty good. Im using a 12at7 tube by the way. I think it still needs some tweaking on the input caps and tone stack. The LM317T does need a heat sink so I just made one out of a piece of aluminium i had lying around. Anyway just thought you guys might be interested
Cheers JOHNO
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on June 25, 2008, 12:06:35 PM
hello again (and thanks for answers again!)

I've decided to keep the tone control. I'll put 3 switches in, was planning on using 1st one to reduce the gain to a clean boost; 2nd one for tone control on/off; 3d one for some other interesting tweak.

Any good tone mods to add to the last switch?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cheeb on June 25, 2008, 07:49:51 PM
Hey Johno, what voltage regulator do you mean? I'd like to supply mine with more than 12 volts to see what the outcome is. It would be great to have a power supply for the VC that has like a rotary switch for voltage selection.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: JOHNO on June 25, 2008, 11:14:21 PM
Cheeb, check page five of this thread. Theres is a schemo there that dano came up with that has the voltage regulator in it. I that schemo dano uses a 6111 tube. Just apply the regulator section to the schemo on page one.
I have a question for dano, with the LM317T the spec sheet says that the tab is conected to the out pin of the regulator so I would think that means I need to keep the tab isolated from ground? Is that correct.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 26, 2008, 04:10:49 AM
hello again (and thanks for answers again!)

I've decided to keep the tone control. I'll put 3 switches in, was planning on using 1st one to reduce the gain to a clean boost; 2nd one for tone control on/off; 3d one for some other interesting tweak.

Any good tone mods to add to the last switch?

What you could do, is to make a input cap selector.
With a rotary switch, just like I did with my Pepper Shredder.
So you can select the amount of bass That comes in.
For the smallest cap you have to use a good ceramic or  Silver Mica .
I used a 680pF.
 just look here :  http://www.diystompboxes.com/smfforum/index.php?topic=63479.500
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on June 26, 2008, 06:24:55 AM
....with the LM317T the spec sheet says that the tab is conected to the out pin of the regulator so I would think that means I need to keep the tab isolated from ground? Is that correct.

That is correct, isolate the tab.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on June 26, 2008, 06:14:43 PM

What you could do, is to make a input cap selector.
With a rotary switch, just like I did with my Pepper Shredder.
So you can select the amount of bass That comes in.
For the smallest cap you have to use a good ceramic or  Silver Mica .
I used a 680pF.
 just look here :  http://www.diystompboxes.com/smfforum/index.php?topic=63479.500


Thanks, sounds nice!
Yeah, all I got ordered is my 3 two way switches, sounds good to dedicate the last one to this. If you'd have to choose one of the caps (other than standard) which one would you make switchable? (which one is the most useful you think?)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: rm -rp ./Matt* on June 26, 2008, 11:39:26 PM
This is a nice thread, just about to start my valvecaster build, it seems that voltage regulation is a big issue.

Should I build a voltage regulation box (wall wart 60 or 200 perhaps?) and should I set to voltage to 12.6v?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 27, 2008, 12:45:40 AM
Thanks, sounds nice!
Yeah, all I got ordered is my 3 two way switches, sounds good to dedicate the last one to this. If you'd have to choose one of the caps (other than standard) which one would you make switchable? (which one is the most useful you think?)

I did it with the input-cap.
For the valveCaster it's C1.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 27, 2008, 12:56:49 AM
This is a nice thread, just about to start my valvecaster build, it seems that voltage regulation is a big issue.

Should I build a voltage regulation box (wall wart 60 or 200 perhaps?) and should I set to voltage to 12.6v?

The DC- wall wart should be at least 500 mA.
You could use a LM7812 with a diode (1n4148) on the centre pin (cathode to ground), this sets you up for about 12.6 volt.
And solder it on the input jack for the power supply, together with the 100 uF cap.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: rm -rp ./Matt* on June 27, 2008, 01:12:15 AM
This is a nice thread, just about to start my valvecaster build, it seems that voltage regulation is a big issue.

Should I build a voltage regulation box (wall wart 60 or 200 perhaps?) and should I set to voltage to 12.6v?

The wall wart should be at least 500 mA.
You could use a LM7812 with a diode (1n4148) on the centre pin (cathode to ground), this sets you up for about 12.6 volt.
And solder it on the input jack for the power supply, together with the 100 uF cap.

Thanks Jimmy, by the time my tubes come in the mail I should properly know what your talking about and add it to the layout design :) My brain is working overtime learning all this stuff
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on June 27, 2008, 06:46:27 AM
Well ive been messing around with this circuit today and while its supposed to run at 9 or 12 volts and it sounded ok at those voltages I just thought it was a waste. So I whipped up dano's voltage regulator using the LM317T and used a 5k trim pot because thats all i had on hand. Hooked it up to my bench top power supply and cranked it up to 20vdc.
Set the heaters to about 9v just to get the tube cooking a bit and it sounds pretty good. Im using a 12at7 tube by the way. I think it still needs some tweaking on the input caps and tone stack. The LM317T does need a heat sink so I just made one out of a piece of aluminium i had lying around. Anyway just thought you guys might be interested
Cheers JOHNO

  Hi JOHNO, you want your heaters at a minimum of 12.2 volts, 12.6 is optimum for 12A_7 tubes. Better sound and longer tube life.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on June 27, 2008, 06:55:39 AM
Hi everybody,

Has anyone tried some 6112 tubes ? I can't get any sound of it  :( Maybe the 6112 does not work at all with low voltage ???? After all tubes are designed for high voltage...  :-\

- I've build a Voltage regulator for the heater -> OK :  6,3v, the tube lights up

- At beginning I was trying to replace the JFET in the first stage of a working distorsion breadboard project just to test, and as is what not working I build on another breadboard the first stage of the valvecaster without more success I must say. Only difference : I run it at 24V (so I replaced the 220K  by a 1M pot to be able to set the bias...)

I've check, double check, and check again pins layout but it is good. (Even tried to invert anode/cathod just to be sure...) I don't get any sound and when trying to bias the tube at half supply voltage, there is almost no drop voltage on the bias pot (24-> 22V with a 1Meg pot set at full), meaning there is almost no current flow through the tube I would say  ???

What's you opinion ? Should I forget using these tubes ?

Thanks

Hi Darkness,

On page three there was this reply from Jered:

Dano, I forgot to add, I tried 6112 and 6021 tubes and the sounded horrible. That's all.
  Jered

So there most be comming some sound out of your tube, even when it sounds like sh*T !!!
I think with 24 volts this tube will sound great.
There has to be something wrong with your build.
Keep in mind that jered only used 9 volts!

I hope that you will find what is wrong!  :-\

  hehehe...that was with the sub minis directly replacing the 12AU7's at 9 volts.  With a few tweaks and at higher voltages the sub minis sound like little tube amps. Everything from low/mid gain crunchy to high gain endless sustain. I'm in the middle of doing a small write up right now and schems for circuits using 6021's and 5784 pentodes. I was hoping to have the write up done by now but work has been hectic so time has been an issue. Hopefully I'll have it done within a week or so.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 27, 2008, 07:00:46 AM
I'm in for the high gain circuits...Eager to see your work!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: JOHNO on June 27, 2008, 07:18:20 AM
> you want you heaters at a minimum of 12.2v,12.6 is optimum for 12A_7 tubes.

Thanks jered, I thought we were shooting for 6.3v. Is the 6.3 for the 6111 tube is it? I'll crank up the voltage on the heaters a bit more ,Thank you . JOHNO
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on June 27, 2008, 07:39:22 AM
Thanks, sounds nice!
Yeah, all I got ordered is my 3 two way switches, sounds good to dedicate the last one to this. If you'd have to choose one of the caps (other than standard) which one would you make switchable? (which one is the most useful you think?)

I did it with the input-cap.
For the valveCaster it's C1.

Oh sorry, asked for the wrong thing heh, what I meant to ask was
which value of C1 other than standard 47nF would you choose if you only could choose between two values (a two way switch)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 27, 2008, 09:18:33 AM
> you want you heaters at a minimum of 12.2v,12.6 is optimum for 12A_7 tubes.

Thanks jered, I thought we were shooting for 6.3v. Is the 6.3 for the 6111 tube is it? I'll crank up the voltage on the heaters a bit more ,Thank you . JOHNO
Yeah, the 6111 tube only work with 6.3 volt.
The normal tubes work with 6,3 volt when using the center tap as ground.(this also doubles the current you use)
Otherwise 12.6 volt without the center tap.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 27, 2008, 09:25:59 AM
Oh sorry, asked for the wrong thing heh, what I meant to ask was
which value of C1 other than standard 47nF would you choose if you only could choose between two values (a two way switch)

You could try 2n2 or 4n7.
But you could also try some other values (those caps are not that expensive)
Experiment a littlebit, and when you find the right ones you like, put them in!! ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on June 27, 2008, 09:29:08 AM
I'm in for the high gain circuits...Eager to see your work!!!  :icon_wink:

Yep so am I!!!
 :D
Title: TWINCASTER
Post by: Renegadrian on June 27, 2008, 05:58:42 PM
Jimmy, and all my fellow tube friends, did you check the VERO double valvy layout I added in the gallery?
it should work but I'd like you to check it...
In the LAYOUT GALLERY search for TWINCASTER.

PS actually it's 2 layout, with and without the R1 at the beginning at the second stage. Someone said it's better to add that res...
Title: Re: TWINCASTER
Post by: Jimmy-H on June 30, 2008, 05:40:02 AM
Jimmy, and all my fellow tube friends, did you check the VERO double valvy layout I added in the gallery?
it should work but I'd like you to check it...
In the LAYOUT GALLERY search for TWINCASTER.

PS actually it's 2 layout, with and without the R1 at the beginning at the second stage. Someone said it's better to add that res...

Hi Adriano,

Sorry that I didn't check it earlier.
I never use stripboard.
But as far as I can see, the layout should work!!  ;)

I used this schemo to check:
(http://i301.photobucket.com/albums/nn69/Joppes60/twincaster.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on June 30, 2008, 10:11:33 AM
Yes, that's from that schem - thanks for checking, Jimmy!!! I appreciated that...(http://digilander.libero.it/le.faccine/faccinea/amici/103.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: stephanovitch on July 01, 2008, 11:56:27 AM
Hi,
do you think it's possible to supply the heat circuit of 12ax7 with only 3,3V for one triode section?
I ask this because the cooltron serie of Vox, use this technic to decrease current consumption.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on July 01, 2008, 01:34:42 PM
Hi,
do you think it's possible to supply the heat circuit of 12ax7 with only 3,3V for one triode section?
I ask this because the cooltron serie of Vox, use this technic to decrease current consumption.

3.3v for one triode? There are two triodes in a 12ax7, therefore 3.3v for each is 6.6v right? The two triodes share a common heater - you could supply the heater with 6.6v using the centre tap, but 6.3v is preferable. However, using the centre tap at 6.3v consumes 300ma, whereas using 12.6v and not using the centre tap uses just 150ma.

Having said that, running the entire circuit at 9v ( as some people do, including myself) give the heater just 9v, and the circuit works just fine.

So, the rule seems to be: less volts = more ma
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on July 01, 2008, 04:02:40 PM
.......................although interestingly enough, all the Cooltron range are rated at 95ma...............

http://www.voxamps.co.uk/pedals/cooltron.asp
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on July 01, 2008, 04:17:28 PM
Hi,
do you think it's possible to supply the heat circuit of 12ax7 with only 3,3V for one triode section?
I ask this because the cooltron serie of Vox, use this technic to decrease current consumption.

3.3v for one triode? There are two triodes in a 12ax7, therefore 3.3v for each is 6.6v right? The two triodes share a common heater - you could supply the heater with 6.6v using the centre tap, but 6.3v is preferable. However, using the centre tap at 6.3v consumes 300ma, whereas using 12.6v and not using the centre tap uses just 150ma.

Having said that, running the entire circuit at 9v ( as some people do, including myself) give the heater just 9v, and the circuit works just fine.

So, the rule seems to be: less volts = more ma

First, VOX uses 12Au7 TUBES.
I don't think 12AX7 sound very well with that low voltage.
I never tried to use a heater voltage of 3.3 volts.
But eeh the VOX pedals are working!
I don't know how it sounds.

Less voltage isn't always more Current.
Because if you use 9 volts without the centre tap, the current Will be less then 300 mA.(just maths ;) )

So just try, and let us know, what it sounds like with 3.3 volt!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on July 01, 2008, 04:56:49 PM
"Here’s what makes the COOLTRON system tick. The COOLTRON circuit basically operates by using two very special signal paths. The first is the “servo circuit,” which provides the right conditions between the plate of the tube and the grid. This achieves controllable, stable parameters for the tube and provides the correct operating conditions for the tube to function as it would if run at a higher voltage. The second circuit is a patented power supply that provides a low voltage, low current supply to the heater elements in the tube. Since the tube is now running at such a reduced supply level, the anode current is much smaller than normal. This means that the amount of heat required at the cathode to achieve sufficient cathode current emission is much smaller – hence the ability to run the heaters at a lower level and for COOLTRON pedals to run for 16 hours on 4 x AA batteries!"

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on July 01, 2008, 05:52:43 PM
"Here's what makes the COOLTRON system tick. The COOLTRON circuit basically operates by using two very special signal paths. The first is the “servo circuit,” which provides the right conditions between the plate of the tube and the grid. This achieves controllable, stable parameters for the tube and provides the correct operating conditions for the tube to function as it would if run at a higher voltage. The second circuit is a patented power supply that provides a low voltage, low current supply to the heater elements in the tube. Since the tube is now running at such a reduced supply level, the anode current is much smaller than normal. This means that the amount of heat required at the cathode to achieve sufficient cathode current emission is much smaller – hence the ability to run the heaters at a lower level and for COOLTRON pedals to run for 16 hours on 4 x AA batteries!"



Hee Rick you really did your research!!!! :icon_wink:
Title: tube?
Post by: Renegadrian on July 01, 2008, 06:30:09 PM
I don't know if you agree with me, but I have a bad opinion about those hybrid pedals, the Valvy is special to me as all the sound comes from the tube only, and the tube itself is not surrounded by trannies and other things...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on July 01, 2008, 07:23:04 PM
I don't know if you agree with me, but I have a bad opinion about those hybrid pedals, the Valvy is special to me as all the sound comes from the tube only, and the tube itself is not surrounded by trannies and other things...

Yes Adriano I agree - the less components the better.

At the moment I'm working on a circuit which may be of interest - a single tube tremolo - 9 volt of course. The one on the breadboard uses a 6111 but I will use a 12au7 for the finished pedal. It uses a LM13700 VCO, and has two speeds, selectable by stompswitch. It slowly speeds up/slows down when you stomp the speed change switch. There is a nice light valve crunch if you play harder. I will post it when its finished!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: JOHNO on July 01, 2008, 10:10:52 PM
Great work freq ,its crossed my mind to make a valve trem like in the old fenders but im not that switched on yet. Im just wondering how long it will be before some company stooge gets hold of the valvy and we start seeing them in the stores.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on July 01, 2008, 10:45:04 PM
So, who is going to be the first to do a valvecaster->386->1 to 1 matching transformer?

There's magic to be found there....
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on July 02, 2008, 06:26:36 AM

Hi Dano12, I was just wandering if it would be ok to add a phase inverter stage, possibly plugged in a 1:1 transformer at the end of a valvecaster or valvecaster-like  ;)

I need more parts to test this....I will have to wait for my next parts order ! By the time, do you think the idea of the phase inverter / transformer is relevant in such circuit ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Aren on July 03, 2008, 01:12:30 AM
So, who is going to be the first to do a valvecaster->386->1 to 1 matching transformer?

There's magic to be found there....

I'm puzzled here... a transformer after a 386?  ???
I had a few thoughts about adding an impedance matching transformer after my cleaned out version of the valvecaster that will create a tube DI, but after a 386? what's the deal there?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 03, 2008, 08:54:31 AM
gaah!

Took long enough for the banzai shipment, (with several items backordered - including the tube).  When I finally get it.... there's no box. They forgot the box. Getting pretty pissed...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on July 03, 2008, 09:02:28 AM
gaah!

Took long enough for the banzai shipment, (with several items backordered - including the tube).  When I finally get it.... there's no box. They forgot the box. Getting pretty pissed...


For my last orders some items were back ordered too. It took a bit more than one week to be shipped ... and most of the time I usually get the back ordered parts in a separate shipment (at no extra shippment costs) Last time I thought they forgot one item (as they did not have noticed it on the order list as they usually do)  But I finally got it a couple of days later

personaly I think the service is good  :) but you need a bit of patience  ;) Good luck !
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 03, 2008, 09:13:30 AM
gaah!

Took long enough for the banzai shipment, (with several items backordered - including the tube).  When I finally get it.... there's no box. They forgot the box. Getting pretty pissed...


For my last orders some items were back ordered too. It took a bit more than one week to be shipped ... and most of the time I usually get the back ordered parts in a separate shipment (at no extra shippment costs) Last time I thought they forgot one item (as they did not have noticed it on the order list as they usually do)  But I finally got it a couple of days later

personaly I think the service is good  :) but you need a bit of patience  ;) Good luck !


Yeah, I've only shopped there once before, that time everything worked perfectly. I only wish they had some kind of stock info about the parts available.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: LMJS on July 03, 2008, 09:28:32 AM
Don't feel so bad.
My last order from Small Bear was the opposite.
They sent the box and forgot the rest of the order.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 03, 2008, 09:30:39 AM
Don't feel so bad.
My last order from Small Bear was the opposite.
They sent the box and forgot the rest of the order.


hahah ok, now thats definitely worse
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 03, 2008, 11:02:07 AM
Yeah, excellent service after all, shipped the box straight away   :icon_biggrin:
Title: SKULL VALVECASTER
Post by: Renegadrian on July 07, 2008, 04:25:31 PM
(http://einarkramer.890m.com/UsePage/50px-Skull_and_crossbones.png) Valvecaster IV (http://einarkramer.890m.com/UsePage/50px-Skull_and_crossbones.png)

I made this for Santa Pazienza bass player - It's a local band here in Rome - it means "Holy Patience"
Took their logo, swapped the candle for the tube...et voila'!!!

(http://img297.imageshack.us/img297/6206/diyforumva6.jpg)(http://a892.ac-images.myspacecdn.com/images01/63/l_162c162cad4a3e14c6896317a397dbf3.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on July 07, 2008, 05:09:58 PM
Really looks great Adriano!
Nice job!! :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on July 07, 2008, 05:12:38 PM

Yes great job ! Happy bass player !  :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: letsgocoyote on July 15, 2008, 11:36:59 PM
So I just ordered me a tube and socket finally, after this thing goign 32 pages I will take on a valve caster.  i already have a pretty cool enclosure for it too!  should come out looking pretty neat.


anyone TRY it with batteries?
of course its going to chew through them, but i could see this going on a mini busking pedalboard, so long as it doesnt blast through batteries any faster than my rc-2 loop station.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on July 16, 2008, 12:07:53 AM
anyone TRY it with batteries?

I got 6 minutes. Once the battery starts going, the voltage output drops and the sound becomes mush.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: letsgocoyote on July 16, 2008, 02:59:16 AM
figures.  i wonder what difference perhaps 6AA batteries could make instead.  regardless im excited for the build
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on July 16, 2008, 03:20:56 AM
regardless im excited for the build

It's a great build. I gave my twin channel version to a friend for his birthday, so now I have an excuse to build another for myself  :icon_mrgreen:
I'm going with a no-tone pot tagboard version this time.
Title: Valvecaster No Tone
Post by: Renegadrian on July 16, 2008, 03:39:16 AM
I'm going with a no-tone pot tagboard version this time.

No tone Valvy? (http://digilander.libero.it/le.faccine/faccinea/perplesso/1122.gif)
Well...Follow my layout then!!!  :icon_wink:
I am so happy I built mine without that 3rd pot...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 16, 2008, 12:10:58 PM
oo mine is turning out nicely... if I had a good camera at hand I would give you a little look inside (its pure spaghetti mayhem)
Havent got a tube to test it with, so I have no idea if its working or not. But its pretty neat on the outside, always something ei?

Here is a picture of the layout, I took renegadrians layout and modded a bit, and put the parts on a board. Probably not the easiest way to build this thing but hey
3 switches for different mods, tone on/off, 2 different input caps and 2 different values on R1&R2

(http://i18.photobucket.com/albums/b110/aka_Basse/render.gif)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on July 16, 2008, 02:20:08 PM
Hi aka bass,


Sure looks like a lot of fun!!
Bur where are the meatballs??  ???
No spaghetti without the balls!!
No just kiddin'.

Just let us know how it all sounds like!
And I'm very curious how it gonna look altogether!

have fun building it!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on July 17, 2008, 02:00:12 PM
Here is a picture of the layout, I took renegadrians layout and modded a bit, and put the parts on a board. Probably not the easiest way to build this thing but hey
3 switches for different mods, tone on/off, 2 different input caps and 2 different values on R1&R2

(http://i18.photobucket.com/albums/b110/aka_Basse/render.gif)


Your point to point layout is very cool!  Thanks for sharing!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: comfortably_numb on July 17, 2008, 07:52:09 PM
Okay, here's another little mod for the Valvecaster:

A usefull tonal variation can be achieved by implementing a switchable negative feedback.

Put a 22k resistor and a spdt switch between the output and the cathode of the second stage (lug 8 ).
You can also make a "bass boost" filter out of it by inserting a capacitor between there as well.
I currently have a 0.056uF cap in series with the resistor. This removes some of the mid range and helps keep things a little bit more together. It sounds nice and clean at low gain settings and it also sounds pretty good with everything maxed. More defined puch in the bottom and not so shrill. I've tried this with larger caps as well but it tends to get a bit too boomy.
All in all this is a nice little mod which will tame the gain a bit. Nothing dramatic, but it helps if you want to tune the thing for a more clean boost.


I'm interested in the use of this negative feedback idea.  Is this similar to the theory behind the inverting input on an opamp, where what you feed back suppresses what comes out again?  So by allowing high frequencies through with a capacitor you actually suppress them in the output? 

Would there be a way to insert a more intricate tone shaping network, possibly bleeding highs to ground to accentuate them at the output?  Is there a way to implement something like the feedback loop of the Rat distortion, where there are different gains for different parts of the frequency spectrum? 

I'm I completely off base here?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: comfortably_numb on July 17, 2008, 10:40:31 PM
I've explored the negative feedback idea some on my own.  It could all be for naught, as I'm not sure that the theory is sound.  But based on my work with inverting opamp circuits, and the fact that someone suggested negative feedback in this one, I've come up with my own variation.

The schematic below is the Valvecaster with the following modifications:

Input cap reduced from 47nF to 10 nF to tame bass.
Coupling cap reduced from 47nF to 6.8nF to further tame bass fed to second gain stage.
Negative feedback network established between output of second gain stage and cathode (pin 8) to reduce gain in this stage and to shape frequency response.

The idea behind this is to make up for loss of bass in the eariler stages.  It won't distort so much in the bass and get flabby, but I still want a full bottom end.  This will also add some top end sparkle (apparently) because of the dip in the mids.

The feedback is a bell curve bandpass, with the lows being slightly more attenuated than the highs.  This of course, should have the opposite effect on the output, giving a mid dip (hopefully not a scoop) with a good amount of bass and treble. 

I don't have the resources to build this at the moment, so if anyone gives it a shot, please post the results.  Also, if my theory is totally flawed, let me know.

Here's the schematic - I know it says +9V, but I intend to build it at 12V.  Also, for a slightly flatter response, change the 200k resistor in the feedback network to 500k.  This is probably where I'll start.
(http://i78.photobucket.com/albums/j93/joeydail268/IMG_5538.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on July 18, 2008, 01:32:13 AM
Interesting!
I'll have to get your mods on the breadboard next week... I like the idea a lot  ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 18, 2008, 07:45:30 AM
I wanted to trie it with a 12ax7/ecc83 tube since my 12au7 is on its way. During this test I made 2 mistakes:

I mounted the DCplug the wrong way on the adapter, and I had wired one of the + wires to the wrong pin on the dc jack (thought that both + pins had connection all the time). So when I fixed this it still doesnt work - did I blow the 7812? It got pretty warm! How do I test the regulator without taking it out? (its buried beneath the cable spaghetti)

The led never lit, and I tested and it was in the right "direction".


!!edit: Ok never mind, im too stupid for this kind of stuff. Wired the + wires from the wrong pin AGAIN, but now the LED lights and everything. But there is no sound whatsoever. Can this be because of the 12ax7? If the box worked it would still give me some sound with this tube, right?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 18, 2008, 11:22:50 AM
YES!!! It works!!! Playing with 12ax7 now, cant wait to my hands on a 12au7!

Sitting and measuring values and thinking and going mad... and then - without doing a thing - I plugged it in... and it worked!
Title: 12ax7???
Post by: Renegadrian on July 18, 2008, 01:11:19 PM
12ax7??? Hey, how did you make it work??? How's the sound? And how much gain?
In the standard circuit the ax7 was too "boomy" and the sound was really bad...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on July 18, 2008, 01:27:04 PM
aka_basse,
I'm curious too.  The EH AX7 I was using didn't sound to good.  the EH AU7 sounds much better.  Did you use the layout you posted?
Title: Re: 12ax7???
Post by: aka_basse on July 18, 2008, 01:45:18 PM
12ax7??? Hey, how did you make it work??? How's the sound? And how much gain?
In the standard circuit the ax7 was too "boomy" and the sound was really bad...

Well, to me it sounds pretty ok. Its the standard curcuit with a few switchable mods, (including your favorite the tone-knob killer). Using it with the clean channel of my amp (valvestate 80v) works great, the channel otherwise sounds pretty boring. The valvecaster added some compression and with gain up I got a pretty good crunchy tone (the bass sounds kinda bad, but it always has on the clean channel). Used as a booster on the lead channel I actually think my stratoblaster made a better job (and together there is way too much wierd noise and distortion). So it wasnt bad. Perhaps not that amazing, but Ill have to compare it to another tube to get some perspective. Same goes for the gain, hard to say without comparing. The tube I use is a Marshall. The whole reason why Im not using a 12au7 is because im waiting for my order from banzai, and I wanted to see if the box worked.

One problem is hum when used with lead channel of amp. I have a voltage regulator in it, so is it just bad wiring or something?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Darkness, Darkness on July 18, 2008, 03:20:02 PM
On my side, thanks to this thread, I've played with 12AX7, more in a marshall plexi configuration than a valvecaster I must admit... and it works very great on my Emery Sound super baby heads: BIG sound  :o amazing ! :) But when trying it on the clean channel of my Marshall JCM900 it sounds awfull...a thin light dirty clean sound instead of the big roar... It looks like the gain from this setup (powered in 24V) is not so high in the end.

Is it the same for you guys who tried some 12AX7 in the valvecaster ? Or maybe it is linked to the plexi design  : I believe the distorsion is coming for a major part of the power section of this amp, not the preamp ? Well the "only" 24V" might be in cause too.... but regarding the so good results on the emery sound (which was my first goal) I 'll continue experimenting in this direction.

In my next parts order, I will try to add a phase inverter section with negative feedback ... and see what is happening.... For the moment I am trying to understand how phase inverters and output transformer works and what I could try ???  ??? ??? ??? I wander if an isolation transformer right after a classic marshall phase inverter design (so without power amps tubes...)  could work in a stompbox design ??? ???  Yeah, that's a pretty strange (maybe stupid) idea I have....  :P ;D

Anyway, once I'll have my final build, I'll share with you guys !
Title: PEPPER SHREDDER
Post by: Renegadrian on July 22, 2008, 09:50:11 AM
Finished my take on the PEPPER SHREDDER using my layout here http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PEPPER+SHREDDER.jpg.html (http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PEPPER+SHREDDER.jpg.html)
It works, altough I forgot to add C10 (220uF electrolytic) between 12v and ground. (I'll update the layout soon)
Put it in, and added a 7812 at the DC jack, I got a really good overdrive, but a countinuous hiss is coming as soon as I put the wall wart into the DC jack...
Any hiss hint??
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 22, 2008, 11:00:08 AM
Heres some pictures of mine, more in the pictures thread

(http://i18.photobucket.com/albums/b110/aka_Basse/box1.jpg)
(http://i18.photobucket.com/albums/b110/aka_Basse/box5.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: comfortably_numb on July 22, 2008, 05:18:18 PM
aka_basse - where do you get those rails?  And also the small tube protector?  I like the look of the tube sticking out, but don't think I'd be comfortable without that kind of support.

Thanks,
Joey

Anyone gotten a chance to try out my mods?  I've got tubes coming, but I can't wait to know if it works!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Pushtone on July 22, 2008, 05:58:28 PM
Great looking pedal aka. A design after my own heart with roll bars and tube on top.
Those toggles are well protected too.



You can lower the height of the tube by using standoffs on the inside.



(http://www3.telus.net/david65/pedal-pics/shakatube/shaka-tube-34.jpg)

(http://www3.telus.net/david65/pedal-pics/bullitt/Tubesocket2.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: aka_basse on July 22, 2008, 07:31:23 PM
Pushtone: Yeah, got the rollbar inspiration from the pedal you posted earlier in this thread
Thanks for the standoff-idea, might do that if Im starting to stomp away the tubes!

Comfortably numb: The rail is a drawerhandle, and the tube protector came with the socket (along with a cover to put over the tube as well)
Title: Valvecaster V
Post by: Renegadrian on July 26, 2008, 11:58:03 AM
Valvecaster V

(http://img353.imageshack.us/img353/3518/260717mb0.th.jpg) (http://img353.imageshack.us/my.php?image=260717mb0.jpg)(http://img244.imageshack.us/img244/6595/260718ju3.th.jpg) (http://img244.imageshack.us/my.php?image=260718ju3.jpg)

Man, I love flames...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on July 26, 2008, 01:41:28 PM
Looks great!

Where does one get those rollbars?

Also is there much of a difference? I have read the thread and there clearly is. I wanna know though if it is worth to build a dual "Caster". One with a 12AU7 one with a 12AT7...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: any on July 27, 2008, 12:42:10 AM
Looks great!

Where does one get those rollbars?

Also is there much of a difference? I have read the thread and there clearly is. I wanna know though if it is worth to build a dual "Caster". One with a 12AU7 one with a 12AT7...

Those are just drawer handles, you can find them at most hardware stores..
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: runmikeyrun on July 27, 2008, 09:27:12 PM
i think home depot carries pink ones with hearts if you really want to be cool  ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tux320 on July 29, 2008, 12:52:30 PM
If I use Renegadrian's schematic for varo with no tone and I want to run it at 9v do I have to modify the circuit in any way?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on July 29, 2008, 01:38:21 PM
No man, just go straight following the layout...you can run it at 9 or 12v - altough we prefer 12v for the heaters, it will work good at 9v.
Let us know when you've done!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on July 30, 2008, 07:23:16 AM
I discovered that there's also a 9AU7 tube - maybe it's less common, but I believe it could be used well for our projects?
After all, it shares all the 12AU7 details but the heater voltage...
http://www.nj7p.org/Tube4.php?tube=9AU7
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on July 30, 2008, 07:31:38 AM
I discovered that there's also a 9AU7 tube - maybe it's less common, but I believe it could be used well for our projects?
After all, it shares all the 12AU7 details but the heater voltage...
http://www.nj7p.org/Tube4.php?tube=9AU7

How interesting. I do feel sometimes that everyones 12au7 Valvecasters running at 9 volts will one day all fail! A quick worldwide Ebay search shows a decent number of 9AU7s, cheap - but all in the USA.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: FlyingZ on August 14, 2008, 08:57:32 PM
Awesome Matsumin pedal and my first non-looper build
(http://i264.photobucket.com/albums/ii166/_FlyingZ/Pic2.jpg)
(http://i264.photobucket.com/albums/ii166/_FlyingZ/Pic3.jpg)
(http://i264.photobucket.com/albums/ii166/_FlyingZ/Pic1.jpg)

The wires grew a bit  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on August 14, 2008, 09:06:10 PM
Nice one!

How did you do such a clean job of those cutouts in the enclosure?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: FlyingZ on August 14, 2008, 09:13:03 PM
Thanks, I drilled three 1/2" holes and filed the remainder. Two holes for the sides.
Title: yeah
Post by: Renegadrian on August 15, 2008, 05:10:39 AM
VERY NICE INDEED!!!  :icon_wink: LOOKS GREAT...
GOOD WORK ON THOSE CUTOUTS!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on August 15, 2008, 10:47:32 AM
This has most likely been covered in this thread (I didn't feel like browsing the 30-some pages to see) but after being fed up with the lackluster sound of my valve caster (I had tried numerous different types of tubes, mods, input cap values, etc...), I decided to wire up two 9 volts and  try running mine at 18 volts.  Holy crap- it sounds.... thousands of times better.  It sounds awesome!  Highly recommended.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 15, 2008, 11:00:28 AM
This has most likely been covered in this thread (I didn't feel like browsing the 30-some pages to see) but after being fed up with the lackluster sound of my valve caster (I had tried numerous different types of tubes, mods, input cap values, etc...), I decided to wire up two 9 volts and  try running mine at 18 volts.  Holy crap- it sounds.... thousands of times better.  It sounds awesome!  Highly recommended.

Yeah, I think so too. I've been playing about with 6111 submini tubes and switched capacitor voltage convertors to get the plate voltage up to 44 volts. I think this helps with the linearity/symmetry of the waveforms. Apparently tubes like higher voltages!

This is an experiment I did recently, the input waveform was a triangular wave, I decided that 30 volts was really good enough for my purposes, there's not much difference once you get above that. The law of diminishing returns:

(http://i210.photobucket.com/albums/bb292/frequencycentral/10441234.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on August 15, 2008, 11:28:15 AM
Maybe I'll try four 9 volts...  ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 15, 2008, 11:29:37 AM
Maybe I'll try four 9 volts...  ;D

Or just one 9 volt, a MAX1044 and some caps n diodes...........
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 15, 2008, 11:35:59 AM
Can the heaters take 18V?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 15, 2008, 12:08:41 PM
Can the heaters take 18V?

No - 12.6 maximum. But the heaters are powered seperately. At least that's how i do it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 15, 2008, 01:55:24 PM
Cool thats what I figured...

I bought a 12V DC 300mA adapter today...is 300mA enough?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 15, 2008, 02:12:16 PM
Cool thats what I figured...

I bought a 12V DC 300mA adapter today...is 300mA enough?

Yup thats good enough, each 12#7 consumes 150ma @ 12 volts. Is it regulated? If not you may want to use a 7812. Also, always a good idea to use a decoupling cap across the power rails. I use 10uf.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on August 15, 2008, 03:29:56 PM
Correct me if I'm wrong, but in this design powering up the heaters would be just for aesthetics, would it not?  Not that there's anything wrong with doing something just for aesthetics; I'm a big fan of doing just that.  :icon_biggrin:

But is there any "sonic" advantage to it?

Again I'm sure it's been covered somewhere in the previous 30 pages, just... you know... lazy!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MusicAudio on August 15, 2008, 03:42:18 PM
Correct me if I'm wrong, but in this design powering up the heaters would be just for aesthetics, would it not?

The heaters are essential for operating a vacuum tube. Without the heaters there would be no electrons for the anode/grid/cathode to play with.

I hope that's what you're asking.

Putting an LED behind the tube would be the kind of thing you'd want to do for aesthetics.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on August 15, 2008, 04:08:11 PM
Yes, for high voltage vacum tube operation, but at 9V the heaters aren't necessary, right?.  Don't the heaters get voltage from pin 9?  Which is left disconnected in the original design.  I could be totally mistaken.

Edit:  Okay, pin 9 is for the heater centertap.  Pins 4 and 5 are for the heaters for each triode. 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 15, 2008, 04:14:16 PM
Yes, for high voltage vacum tube operation, but at 9V the heaters aren't necessary, right?.  Don't the heaters get voltage from pin 9?  Which is left disconnected in the original design.  I could be totally mistaken.

Yes MusicAudio is right, without heaters the electron won't get 'excited' enough to do anything. The tube won't. work.

Pin 9 is left unconnected in this (and many other tube circuits using 12#7) because it is the 'centre tap' for the filament - using the centre tap and pin 4 you can power the heater at 6.3 volts/300ma. Using pin 4 and 5 you can power the heater at 12.6 volts/150ma.

EDIT: OK you got it, I was typing as you were editing!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 15, 2008, 04:18:20 PM
Cool thats what I figured...

I bought a 12V DC 300mA adapter today...is 300mA enough?

Yup thats good enough, each 12#7 consumes 150ma @ 12 volts. Is it regulated? If not you may want to use a 7812. Also, always a good idea to use a decoupling cap across the power rails. I use 10uf.
Its not regulated but I am adding a little regulating board. Add 0.1mF at the start and a 100mF cap after the regulator.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 05:52:22 PM
Having a bit of an issue with my Valve Caster I just finished... :icon_cry:

It doesn't make any sound when engaged...
I get sound though at lug two of the volume pot (output) when I audio probe it. It is much louder than when I probe the inout cap. It is so faint there I can barely hear it. As I go along the circuit it gets louder so that must be good I think.

I get sound also on pin 5, it is very odd... Pin 5 is a heater that is directly connected to B+... This seems like an issue.

Also when all voltages on the pins are super low compared to Rick's postings before (his were like 12V on some spots where as mine were 0.124V)... Btw my readings were with a tube installed...

Its a stock build besides a 4.7mF in parallel with the gain pot to boost gain and a little variable B+ circuit I made.

Help please...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 17, 2008, 06:20:48 PM
Chris, post your voltages and any changes you have made. Best set that variable B+ to 12 volts for your voltage readings (and remove the 4.7mF in parallel with the gain pot), that way the circuit should be similar to mine. You're not varying the voltage to the heater (pin 5) are you? Pin 5 needs to be an unvarying 12 volts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 06:24:34 PM
Chris, post your voltages and any changes you have made. Best set that variable B+ to 12 volts for your voltage readings (and remove the 4.7mF in parallel with the gain pot), that way the circuit should be similar to mine. You're not varying the voltage to the heater (pin 5) are you? Pin 5 needs to be an unvarying 12 volts.
I am using an unregulated 12V DC power supply...It can shoot upwards of 16.5V DC.

With my variable B+ design the overall voltage gets adjusted, I cant set the heaters independently. From my understanding the heaters can work if they recieve too much or too little voltage, it just affects tube life.

All test so far have had the B+ at 13.7V...

Ill readjust and get voltages...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 06:37:09 PM
B+ 12.58V DC

1. 0.2V
2. 0V
3. 0V
4. 0V
5. 0.2V
6. 0.2V
7. 0V
8. 0V
9. 0.1V

Btw without a tube in the voltage seem reasonable considering the circumstances.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 17, 2008, 07:03:52 PM
B+ 12.58V DC

1. 0.2V
2. 0V
3. 0V
4. 0V
5. 0.2V
6. 0.2V
7. 0V
8. 0V
9. 0.1V

Btw without a tube in the voltage seem reasonable considering the circumstances.

Here's mine again:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

Your voltages are extraordinary. They were taken with the tube in, yes?

The first thing I would say is that I think giving the heaters anymore than 12.6 volts is bad - giving them less would shorten the life - but giving them more will probably burn them out - like a lightbulb thats rated at a certain voltage if you give it too much. You need to set the heater independently at 12 volts. Maybe you should consider a 7812 voltage regulator for that.

Is the heater glowing?

I just did a quick test on a tube that I know to work. Not in a circuit, just the tube. The resistance between pins 4 and 5 reads 10 ohms. The resistance between pins 4 and 9 (the heater centre tap) reads 5 ohms. Thats a healthy heater. Take your tube out and do this test, post your results.

I've noticed that this circuit doesn't like some power supplys - my brother tried one which seemed appropriate but all he got was hum, we plugged it into my power supply and it worked fine. You should run it from a (new) 9 volt battery, then we can concentrate on if the problem is just the circuit or the power supply.

It occurs to me that nearly all you voltages are 0 volts - I don't know what happens if you blow a tube heater - but maybe it shorts out the whole tube, and therefore the entire circuit - which would explain your short circuit. If you circuit shorts, it may cause your power supply to fail and/or shut down. Pins 1, 5 and 6 should be reading at least some reasonable positive voltage, as they are closest to the power supply. If there's nothing at pin 5 the heater isnt powering up, the electrons wont get excited! they won't do their thing.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 07:16:05 PM
Yes I had a tube in... Ill try that test you suggested.

The heater does not glow at all.

I have another 12AU7 and more power supplies (and a battery) that I can try.

My power supply is 300mA...is that enough..what does your draw? Earlier in the thread someone said 500mA is the minimmum.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 17, 2008, 07:28:25 PM
The heater does not glow at all.

Try just powering the heater from a battery, +ve to pin 5, -ve to pin 4, with the tube out of the circuit. Turn your room lights out. The warm up time of the heater is 11 seconds. If it hasn't lit up within 30 seconds its dead.

supply is 300mA...is that enough..what does your draw? Earlier in the thread someone said 500mA is the minimmum.

Using pins 4 and 5, the current draw is 150ma.

EDIT: Although pin 9 is not connected in this circuit, it will show a voltage of approximately half the voltage going into pin 5. Make sure pin 9 (or its socket tab) isnt touching anything else,

12AU7 datasheet: http://www.guitaramplifierblueprinting.com/files/GE-12AU7.pdf
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 17, 2008, 07:42:17 PM
The heater does not glow at all.

My power supply is 300mA...is that enough..what does your draw? Earlier in the thread someone said 500mA is the minimmum.

http://www.nj7p.org/Tube4.php?tube=12AU7

It seems a heater issue...check back all the connections, either build my verified vero layout and remove that extra cap (you can install it back when it's workin')
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 07:46:25 PM
Threw in a battery and it works... yeah!

There was a lot of gum though...it stopped when I touched a ground point thouhg, so I gotta figure that one out.

Did this not work because the power supply could supply enough current?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 17, 2008, 07:52:20 PM
Threw in a battery and it works... yeah!

Excellent!

There was a lot of gum though...it stopped when I touched a ground point thouhg, so I gotta figure that one out.

Gum I can live with, it's hum I hate. Bad earthing somewhere.

Did this not work because the power supply could supply enough current?

I don't think tubes like unregulated, unfiltered power supplies. You need a really good supply for this one.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 08:01:32 PM
I was using a LM317...

I tried another 300mA 12V DC power supply and got low voltages again...

I guess I gotta buy a third power supply... (this will be the 3rd one in 2 days :icon_evil:)

Can you measure how much the effect is drawing for me?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 17, 2008, 08:09:54 PM

I was using a LM317...

That should keep the voltage stable - just don't give the heater more than 12.6 volts.

Can you measure how much the effect is drawing for me?

Tell me how and i will - not sure how to do this - I'm going from the datasheet on curent draw.

FYI, I am able to run two 12AU or two 6111 from my 12 volt / 500ma wallwart with ease.

Going to bed now - it's 1am her in the UK!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 17, 2008, 08:15:01 PM
I'm in a bit of a quandry here.....

I really want to build this pedal (as well I probably will) - my problem is this:

My pedalboard is run by 2 Voodoo Labs Pedal Power II's - I have the option of 9v or 18v....if I want 12v I'll have to add a wall wart to the operation somewhere - not my best option.
Is there a way to run 18v into the circuit but "resistor" it down so it only sees 12v input ?

Thanks, Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 08:17:32 PM

I was using a LM317...

That should keep the voltage stable - just don't give the heater more than 12.6 volts.

Can you measure how much the effect is drawing for me?

Tell me how and i will - not sure how to do this - I'm going from the datasheet on curent draw.

FYI, I am able to run two 12AU or two 6111 from my 12 volt / 500ma wallwart with ease.

Going to bed now - it's 1am her in the UK!
You set your meter to measure current and put it in series with the B+.

I measure the current draw with a battery and it was only 0.12A... My power supply should work fine,  :icon_evil: :icon_evil: :icon_evil:

Thanks for the help btw
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 08:19:06 PM
I'm in a bit of a quandry here.....

I really want to build this pedal (as well I probably will) - my problem is this:

My pedalboard is run by 2 Voodoo Labs Pedal Power II's - I have the option of 9v or 18v....if I want 12v I'll have to add a wall wart to the operation somewhere - not my best option.
Is there a way to run 18v into the circuit but "resistor" it down so it only sees 12v input ?

Thanks, Dan
You can use the 18V supply and add a LM7812 regulator inside the pedal so it only sees 12V.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 17, 2008, 08:49:31 PM
I'm in a bit of a quandry here.....

I really want to build this pedal (as well I probably will) - my problem is this:

My pedalboard is run by 2 Voodoo Labs Pedal Power II's - I have the option of 9v or 18v....if I want 12v I'll have to add a wall wart to the operation somewhere - not my best option.
Is there a way to run 18v into the circuit but "resistor" it down so it only sees 12v input ?

Thanks, Dan

Dan, you can also build  one running at 9v - 12au7 seem to work good even at 9v at the heaters, else I'd suggest you to get a 9au7, which is the same tube accepting 9v as heater...You can get one dirt cheap thru the bay (as usual...)
I got one at €4 shipping included, go figure...I'd suggest you also to put a regulator, in that case it'llbe a 7809.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 17, 2008, 08:51:53 PM

FYI, I am able to run two 12AU or two 6111 from my 12 volt / 500ma wallwart with ease.

Going to bed now - it's 1am her in the UK!

Me too, no problem with 500mA
Going to bed now - it's almost 3 am here in the Italy!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 17, 2008, 09:08:25 PM
I'm in a bit of a quandry here.....

I really want to build this pedal (as well I probably will) - my problem is this:

My pedalboard is run by 2 Voodoo Labs Pedal Power II's - I have the option of 9v or 18v....if I want 12v I'll have to add a wall wart to the operation somewhere - not my best option.
Is there a way to run 18v into the circuit but "resistor" it down so it only sees 12v input ?

Thanks, Dan

Dan, you can also build  one running at 9v - 12au7 seem to work good even at 9v at the heaters, else I'd suggest you to get a 9au7, which is the same tube accepting 9v as heater...You can get one dirt cheap thru the bay (as usual...)
I got one at €4 shipping included, go figure...I'd suggest you also to put a regulator, in that case it'llbe a 7809.


well....yeah.....I already bought my 6111's  ;)

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 17, 2008, 09:13:44 PM
I haven't utilized a 7812 yet - but - from doing a quick search - it looks pretty easy.

Get a 7812 with proper output voltage. 7812's have 3 legs 'eh ? 18v into one leg, gnd into the other and 12v out of the other ?

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 17, 2008, 09:23:16 PM
Yep, and ground one leg.

Make sure you get the right "legs" though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: liddokun on August 18, 2008, 12:47:00 AM
I tried going through all the posts and such, but there's a little bit of confusion on my part, so please excuse if I'm asking something already answered.  So this pedal acts like a booster, and not like a distortion?  I understand there won't be a lot of gain, but will it add some colour to my tone and just a bit of crunch?
And also, if I build it stock will it sound decent? 
Thanks a lot!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on August 18, 2008, 01:17:58 AM
And also, if I build it stock will it sound decent? 

Yes. Perhaps a little dark.

It's not an entirely clean boost, even with the gain turned right down. The gain control increases dirt and volume.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on August 18, 2008, 05:41:21 AM
Threw in a battery and it works... yeah!

There was a lot of gum though...it stopped when I touched a ground point though, so I gotta figure that one out.

Did this not work because the power supply could supply enough current?

I don't know If you have solved your problem.
But it seems to me, that there is something wrong with your wiring.
Because there is no supply at all on your measurements.
Just try to connect the supply again and measure the incoming power on the power connector.
If this is good, then measure one side of 220K and so on.
I Hope you will find the problem
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 18, 2008, 08:02:18 AM
I tried going through all the posts and such, but there's a little bit of confusion on my part, so please excuse if I'm asking something already answered.  So this pedal acts like a booster, and not like a distortion?  I understand there won't be a lot of gain, but will it add some colour to my tone and just a bit of crunch?
And also, if I build it stock will it sound decent? 
Thanks a lot!

I would say this circuit is definately an overdrive/distortion - and yes, a very decent sound.

As for cleaner boost, I have found the more resistance between you put between V1A pin 3 (the cathode) and earth, the cleaner the sound. I use a 100K gain pot instead of 50K for VR1, cleans up nicely.

There are a number of other mods people have suggested to clean up the sound and brighten it a little - andrew_k is right, it is a little dark. I trawled this thread a while ago and got together all the mods. I've posted them before, but here they are again:


Possible improvement, depending on context:


"I note that the original schematic and layout specify that the triode at pins 1-3 be used for the voltage gain stage, and 6-8 for the follower.

This isn't usually the best way to do it with a 12A*7.  With battery power or regulated DC going through the heaters, it doesn't matter which triode you use in which position, but if you're using AC or less-than-pristine DC, the triode at pins 6-8 will be quieter, due to the location of the heater pins on the tube.  (You can find mention of this in the data sheets on many 12A*7 series tubes.)"



"I lower the coupling cap between stages for less bass."



"For lowering bass, you could try lowering the value of either the input cap, or the coupling cap between the two tube stages."



"I am bypassing the Valvecaster gain pot with a 2.2nf cap. This helps maintain some brightness when the VC gain is turned down. For the input cap on the Valvecaster I am using a combination of caps to give me 2.7nf. This helps tighten up the bottom end."



"To tame the gain I would lower R2 and R3. 220k and 100k seem pretty high for a low voltage circuit. Even in a regular high voltage amp the normal value is just 100k. So maybe cut them in half."



"if you bring down that 220k to 100k it will def lower the gain a bit.  I built mine with both plate r's at 100k."



"A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot."



"Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain."



"guitarx: replace the 100k resistor with 47k. Replace the 220k resistor with 100k. Beautiful cleans."

   

"To fellow Valvecaster experimenters -- I've currently got this circuit on a breadboard, switching out everything and I have some items of interest to report, especially for those looking for more gain.

The nicest clean sound I've found so far, is with the following mods:
R2 = 100k
R3 = 47k
C1 = 0.1uf
Remove C4 and VR2"



"Finally received that 7812 - mounted with the 100uF filter cap on the dc jack - hiss is just a memory... 
put a 100uF cap across the DC jack (positive leg to positive rail, neg. leg to neg. rail), then, instead of connecting the positive rail directly to the circuit, connect it to the regulator's pin1, ground to pin2, and the circuit to pin3. Then screw it on the enclosure. It is a 7812."
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 18, 2008, 07:03:22 PM
Tried my Valvecaster with a LM7812 and now it works with a power supply!

It dosent seem regulated at all though...not sure if its working (I think this because the voltage is not 12V and there is a bit of added hum).

Also my gain knob did seem be to functioning....now it does nothing.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 18, 2008, 07:17:10 PM
Dismantle it - build it again, even with the vero layout someone made... :icon_redface:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 18, 2008, 07:21:58 PM
Why do you want everyone to use your layout?


I used it anyways...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 18, 2008, 07:41:23 PM
Well, I'm so proud of it... :icon_cool:
Obviously I won't force anyone using it, but I'm glad someone did it and had good results...

Back to your circuit, well...I dunno...You say you got voltage but how's the sound? And the gain won't work...
Did you triple  check every connection???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 18, 2008, 07:57:22 PM
It sounds pretty good... Has more gain than I expected (even though I cant tweak the gain)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 18, 2008, 09:21:33 PM
I saw a post somewhere in this thread that mentioned 150ma to run the pedal. Can anyone verify this ? I'm going to run my pedal with a PPII and it'll only make 200ma max with 18v Y cord (according to Voodoo Labs) - so I'm within spec - I just want to make sure.

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 18, 2008, 09:28:50 PM
I saw a post somewhere in this thread that mentioned 150ma to run the pedal. Can anyone verify this ? I'm going to run my pedal with a PPII and it'll only make 200ma max with 18v Y cord (according to Voodoo Labs) - so I'm within spec - I just want to make sure.

Dan
Mine was drawing 120mA yesterday.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 18, 2008, 09:54:03 PM
I saw a post somewhere in this thread that mentioned 150ma to run the pedal. Can anyone verify this ? I'm going to run my pedal with a PPII and it'll only make 200ma max with 18v Y cord (according to Voodoo Labs) - so I'm within spec - I just want to make sure.

Dan
Mine was drawing 120mA yesterday.

bee-yoo-tee-full

Thanks !

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: liddokun on August 18, 2008, 10:15:26 PM

[/quote]




"A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot."


[/quote]

Think I could toss in a 1m gain pot but change the input cap or coupling cap between the tube stages to tame the mushiness?  Or can I just up the value of the gain pot, but not to 1M, maybe something a bit less?  I have a 500K reverse log pot.  Would that work in increasing usable gain/saturated distorted sound?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on August 18, 2008, 11:29:11 PM
I saw a post somewhere in this thread that mentioned 150ma to run the pedal. Can anyone verify this ? I'm going to run my pedal with a PPII and it'll only make 200ma max with 18v Y cord (according to Voodoo Labs) - so I'm within spec - I just want to make sure.

Dan
Mine was drawing 120mA yesterday.

I also found an interesting tone change when I changed my 9V regulated adapter from a 200mA to a 300mA. 
The tone was much more gritty with the 200mA but not as dynamic.  The 300mA is a more mild OD tone, a little brighter and has a little more dynamics.  I'll try to make a demo as soon as I get some time.

-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 18, 2008, 11:29:31 PM
Gain is at the maximum when resistance is 0.

So going with a bigger value pot isnt really doing...just giving more "clean headroom" until you hit cutoff and the bias goes.

Higher value pots will also make it harder to dial in the right amount of gain for you.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on August 18, 2008, 11:47:01 PM
Just picked up 8 7AU7 valves for $2.50 each (7v heater version of 12AU7) to try with this circuit, the Vibracaster and Pepper Shredder. With an LM317 regulator I'm hoping I can power them off 9v, as the LM317 spec states a 1.2v loss

Just another valve to look out for cheap deals on.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: comfortably_numb on August 19, 2008, 07:16:25 AM
I'm a little confused by this circuit's gain control.  Reports are that gain is at maximum when resistance is at 0.  But what this control does (or should do) is alter the bias.  Center bias for this stage would probably be around 5k somewhere.  Increasing the resistance would push the stage toward cut off, sort of like lowering the forward voltage of a diode clipper.  Eventually, the entire negative side of the waveform would be gone.  In the other direction, decreasing resistance would warm bias the stage, heading toward 0 Grid volts, eventually making the triode a half wave rectifier.  This is what it looks like is happening with the second stage.  It could be grid leak biased I suppose, but 470k doesn't seem enough to give a proper grid bias (probably more like 10M!)

Can anyone offer some theoretical insight as to why this operates the way it does?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: MikeH on August 19, 2008, 02:54:58 PM

I am using an unregulated 12V DC power supply...It can shoot upwards of 16.5V DC.


I'm a little late on this, but I'm pretty sure this thing needs regulated voltage.  I tried mine with an unregulated 12V power supply and it didn't work hardly at all.  Mostly just made noise; a little signal coming through.  But when I use a boss-style regulated 9v power supply, it works fine.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 19, 2008, 03:02:18 PM
The first I made was without the regulator - it worked but hiss was a nightmare - then a 7812 woked me up and hiss was gone...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on August 21, 2008, 01:16:30 AM
Like FrequencyCentral's summary, I've just finished consolidating some notes and diagrams from this fine forum thread.  I was getting tired of opening and closing diagrams so decided to consolidate everything to one document and wanted to consolidate the mods for this pedal. 

Just thought other folks here may be able to use this rather than browse thru 34+ pages of this thread (which is excellent reading by the way) to find tips and mods.  Maybe it will inspire others to build one or two... or three..  or...   :D

http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary.pdf

-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 21, 2008, 01:58:19 AM
I've just finished consolidating some notes and diagrams from this fine forum thread.  I was getting tired of opening and closing diagrams so decided to consolidate everything to one document and wanted to consolidate the mods for this pedal.http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary.pdf

tranceracer, that is a superb piece of work!!

You may like to add the information from this thread: http://www.diystompboxes.com/smfforum/index.php?topic=70212.0

If you're reading this you'll already know that I'm obsessed with 6111 submini dual triodes!

I'm looking at ways of powering a single 6111 heater from a 12 volt supply. The 6111 requires 6.3 volts (300ma) ideally, but 6 volts should be fine.

The only example I have to go on is Dano12's way of powering the Subcaster (http://i210.photobucket.com/albums/bb292/frequencycentral/SubCaster-1.gif), which uses an LM317 and associated parts.

I'm thinking a simple resistor voltage divider would do the trick a little more elegantly.

Just looking at the math:

6 volts divided by 300mA = 20 Ohm

6 volts multiplied by 300mA = 1.8 Watts.


So - I'm looking at a voltage divider using two 20 ohm/1.8 watt resistors. Is this correct?

Next: I only have 10 ohm/3 watt in my parts bin. Am I right in assuming two of these are more than enough?

Finally: Most voltage dividers I've seen for 'vref' purposes include an electro cap (say 10uf) between the vref and earth, should I include one in my voltage divider?

Thanks!

The tubes' heaters allow 300ma to pass when there is 6.3V across them, and they are resistive. That means, as you properly compute, that the resistance of a heater is 6.3V/0.3A = 21 ohms. If you have 12Vdc and want to drive 300ma into you heaters, you can do that easily enough without using a voltage divider by putting a resistor in series with the heater. The resistor is R = V/I = (12-6.3)/0.3 = 5.7/0.3 = 19 ohms. It would dissipate 5.7*0.3 = 1.7W and you'd need to use a 3W resistor to keep it from runnig at about 200C surface temp.

A 20/20 divider will not give you what you think. A divider composed of 20 ohms / 20 Ohms from 12V will gie you 6V only when there is no load on the 'Y"s. This produces 6C only when it's not loaded.

Thank you again R.G., that's just great! Amazingly simple solution.  8)

Summary: Running a 6111 submini tube heater at 6.3 volts from a 12 volt DC supply.

Put a 19 ohms 3 watt resistor in series with the heater.

So - no need for the LM317/220 ohm resistor/1K trimpot.


EDIT: I tried it - it works. I had two 10 ohm 3 watt resistors in my parts bin which I scavenged from an old T.V. set. With 5% tolerance, they add up to 19 ohm in series. They get HOT! But then so does the tube, or an LM317 for that matter! They actually get too hot to touch for more than a few seconds - much hotter than the tube.


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: danielzink on August 21, 2008, 07:12:32 AM
I've benn obsessing over this pedal also......

One thing I'd like to add - I contacted Jimmy H re: the tone stack PCB. It wasn't making sense to me how it was laid out vs his Pepper Shredder PCB on page (25 ? 26?) which has -right on the PCB TS-A (tone stack in) and TS-B (tone stack out).

Here's his reply:

I see what you mean (and it was in Dutch).
And you should discard the volume pot in the layout of the tonestack (because there is already a volume pot on the shredder)
So Connect A with in
                 B    with middle tap of the treble pot
                Aarde with Ground from the pepper shredder.

I also have used this layout for an amplifier of mine, that's why the volume pot is on the layout of the tonestack.



HTH, Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: ehofherr on August 21, 2008, 12:18:49 PM
Thanks Tranceracer......I'm looking to build this pedal.....must get parts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on August 22, 2008, 03:58:51 AM
Rick, thanks for the additional tips!  I've updated the .pdf.  I've also added links to the diagrams to the authors in the thread.

Thanks Tranceracer......I'm looking to build this pedal.....must get parts.

No problemo!  It's the great members of this forum who actually did all the work!  :D  I just consolidated it.

Enjoy!
-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: FlyingZ on August 22, 2008, 11:57:46 AM
Very small review:
I tried it out at an outdoor gig last weekend. I stomped all configurations I could think of and it ended up as a semi-clean lead pedal for songs like sweet Home Alabama. It could slightly overdrive my clean channel without the typical solid-state wimpness.

I tried boosting it with MXR, TS9, and CS-3 which all failed. It worked best alone as a clean channel boost.

I'll give it a try next weekend at another outdoor event but as for now it likely wont make my rig  :icon_sad:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on August 24, 2008, 10:01:30 PM
Very small review:
I tried it out at an outdoor gig last weekend. I stomped all configurations I could think of and it ended up as a semi-clean lead pedal for songs like sweet Home Alabama. It could slightly overdrive my clean channel without the typical solid-state wimpness.

I tried boosting it with MXR, TS9, and CS-3 which all failed. It worked best alone as a clean channel boost.

I'll give it a try next weekend at another outdoor event but as for now it likely wont make my rig  :icon_sad:

Yea I use it by itself to overdrive my amp sim.  It doesn't play well with my other pedals either.  Right now it's the main pedal for the tone I'm looking for.

Here are some sound clips:
Valve Caster boost kicks in at about T-24 seconds. Recording setup: Humbucker (bridge position), valve caster (stock setup), amp simulator, recording rig.
http://www.aronnelson.com/gallery/main.php/v/bK-diystompbox/ValveCasterRiff+001.mp3.html

TranceRiff using ValveCaster Pedal. Valve Caster kicks in at T-23 seconds.
http://www.aronnelson.com/gallery/main.php/v/bK-diystompbox/TranceRiff+003.mp3.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: FlyingZ on August 25, 2008, 11:54:05 PM
Great clips, I love the way the ValveCaster doesn't change the original tone like I'm discovering so many DIY projects do. I really hope to find another good one soon  :P
Two breadboard projects (BluesBreaker and CK721 ToneBender) to finish testing and I will submit a ValveCaster clip.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 26, 2008, 05:55:22 AM
Hi guys, first message here..

I read all this thread many times, there are a lot of great tube projects, and I decided to make my own.

I'd like to thank you for gathering all the "mods" on one post, that is very usefull...


The idea is to make an overdrive pedal out of a Twincaster, and be able to go from barely clean sounds to huge amounts of OD gain (using a 12AY7 tube, which someone told me it was more adapted for OD).

I know that I'm gonna have to breadboard a lot before getting satisfied, but the modslist should help a lot..
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 26, 2008, 06:30:59 AM
Hello and welcome aboard - I am sure your work will be appreciated. Looking forward to see your results!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 26, 2008, 12:44:02 PM
Thank you Adriano, but I'm still a bit confused about something..

In the mods list, we have both version of the gain pot:

Quote
"A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot."

Which means that the higher the pot value (and thereby the cathode resistor value), the higher the gain.

But there's also this:

Quote
"Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain."


Which one is the right one?  ??? ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 26, 2008, 12:49:49 PM

Quote
"A 1M gain pot allows massive, saturated gain. A little mushy in the bass frequencies, but pretty cool. I'm considering putting a "more" switch in, whereby it adds a resistor in series to the regular gain pot."

Quote
"Adding resistance to the plate resistors(R1 and R2) will increase gain. Adding resisitance to VR1, in series with the gain pot, will decrease gain."

Which one is the right one?  ??? ???

The first one is wrong - the triode is at its loudest with the cathode hooked directly to ground. I prefer a 100K gain pot, as this will increase clean headroom.

Everything in the second quote is correct.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 26, 2008, 02:19:34 PM
Thank you Rick!

Okay, I planned my design using a "More Gain" switch, which would have done exactly the contrary as expected if I had followed the first quote's instructions..  ;D


Well, to get more gain the only solution would be to put a switch to increase the plate resistors? I thought about putting a 100k resistor in series with 2nd and 4th triodes' plate resistors (making a 200k equivalent plate resistor).
What do you think about it?

I also noticed that someone here used a 2.2nF bypass cap across the gain pot, to "keep some brightness" when the gain is down. Good idea too..
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on August 26, 2008, 02:24:13 PM
Well, to get more gain the only solution would be to put a switch to increase the plate resistors?

..........or make ALL the plate resistors into pots for a multi knob Evilcaster!!! :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 26, 2008, 03:00:07 PM
Wow, don't tempt me..  ;D ;D


Here's my schematic. So far, it's a beta version: (also available in PDF format, here (http://frankyfuzzfire.free.fr/DIY/LAMPES/LowVoltage/TwinPeaksSchematic.pdf))

(http://frankyfuzzfire.free.fr/DIY/LAMPES/LowVoltage/TwinPeaksSchematic.png)



There is also one thing not to forget: pots don't like the DC current. It would be better for their lifetime to feed them AC signal, and mount them as volume pots. Between 2 VC for example, or as in old Marshall preamps, after the first triode.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on August 26, 2008, 03:21:53 PM
Seems a great circuit...Did you build it yet or it's just a schem?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: slacker on August 26, 2008, 03:35:08 PM
Looks cool :)

I'd change the classic/more gain switch so that the 2 resistors (R4, R5) are permanently connected and use the switch to short one of them out. The way you've got it when you flip the switch you'll momentarily break the connection to the plates which might lead to pops and other nasty noises.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 26, 2008, 03:57:19 PM
@ Adriano: No it's only a schemo, I don't have the parts yet, but when it's the case, I spend some time on the breadboard to make it sound as I want..

@ Slacker: damn you're right, I thought about popping, but this solution was something I didn't think about.. Thank you!


I still don't know whether I put some caps across the gain pots or not.. Anyway there are a lot of values possible, 2.2nF was written on the summup..


Edit: it's updated..  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on August 26, 2008, 06:46:22 PM
On my dual Valve Caster I am using a dual gang 100K B pot. Controls both gains..
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on August 27, 2008, 06:36:56 AM
that's incredible all these little tubes can make.. (speaking about the Vibrocaster), I'm sure it's possible to design a tube wah.. A Wahlvecaster?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cheeb on August 27, 2008, 10:15:30 AM
You can't think of anything that R.G. hasn't done.
http://geofex.com/article_folders/tube-wah/tube-wah.htm (http://geofex.com/article_folders/tube-wah/tube-wah.htm)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: FlyingZ on August 27, 2008, 12:08:14 PM
Here is my plain 12v ValveCaster clip:
http://www.aronnelson.com/gallery/main.php/v/FlyingZ/ValveCaster.mp3.html?g2
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on August 27, 2008, 11:59:52 PM
Very nice clips!  I like how you have your ValveCaster sounds with different tones.  I think I'll have to redo my samples!   ;)

-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 04, 2008, 09:28:49 PM
Wow, I started reading that about three hours ago. Read, digested and puked it all back up again. Man that's a lot of good stuff. Around page 27, I just started scrolling through to look at the pictures because some of them are very lovely. I went to the layout section of this site to look for some of the board stuff, but only could find dano's original. I'm not sure if there is a verified section of layouts, mods, parts and stuff, but if there isn't, that could be a good thing to have.

I also think I'm going to have to try and put one of these together. I really liked the one that used two 12au7 tubes. I was thinking about making them more kind of like two pedals in one instead of one pedal. One footswitch would turn one on and another switch to activiate the next tube for more gain. I would like to only have 2 gains, one volume and one tone. Is that possible with this kind of setup? Then I also read in there somewhere that having a booster in there is a good idea too. So where is the best place for that to go? I was thinking of putting in a stratoblaster because the LB1 or 2 were said to be too muddy. Maybe even a stratoblaster before and after the circuit? Sheesh.

Also, I've only dealt with building a guytronix tube amp and a bunch of pedals, but they dont use 12v adapters. Where can I get one of these that good but also not very expensive, as I am poor.

Thanks  :icon_mrgreen: and sorry if this was all discussed. My mind is fried from the rest of this thread to comprehend the last few pages.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 05, 2008, 01:28:20 AM
quote author=mth5044
I went to the layout section of this site to look for some of the board stuff, but only could find dano's original. I'm not sure if there is a verified section of layouts, mods, parts and stuff, but if there isn't, that could be a good thing to have.
STRANGE, DID YOU SEARCH FOR VALVECASTER? TYPE IT, YOU WILL FIND MY VERO LAYOUTS. OR YOU CAN SEARCH MY FOLDER IT'S AT THE LAST PAGES.


I also think I'm going to have to try and put one of these together. I really liked the one that used two 12au7 tubes. I was thinking about making them more kind of like two pedals in one instead of one pedal. One footswitch would turn one on and another switch to activiate the next tube for more gain. I would like to only have 2 gains, one volume and one tone. Is that possible with this kind of setup? Then I also read in there somewhere that having a booster in there is a good idea too. So where is the best place for that to go? I was thinking of putting in a stratoblaster because the LB1 or 2 were said to be too muddy. Maybe even a stratoblaster before and after the circuit? Sheesh.
NOT A CRAZY IDEA, THAT COULD BE DONE...AND YES A BOOSTER BEFORE THE TUBE COULD SPICE THINGS UP...I'D SAY TILLMAN OR STRATOBLASTER TOO...BUT AS A BOOSTER IS SO EASY TO BUILD (I HAVE SEVERAL JUST TO TRY THEM...)  I'D SAY BUILD THE ONES YOU WANT AND TRY THEM ALL...


Also, I've only dealt with building a guytronix tube amp and a bunch of pedals, but they dont use 12v adapters. Where can I get one of these that good but also not very expensive, as I am poor.
I USE A €5 ONE AND A €7 ONE - CHINESE MADE - THEY DO THE JOB AND WON'T BREAK FINANCES...


Thanks  :icon_mrgreen: and sorry if this was all discussed. My mind is fried from the rest of this thread to comprehend the last few pages.
I BELIEVE YOU'LL BE SAYIN' "HOW THE HELL CAN SUCH A SIMPLE CIRCUIT BRING OUT THESE SOUNDS!!!!" - ACTUALLY I DID...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on September 05, 2008, 01:47:20 AM
Wow, I started reading that about three hours ago. Read, digested and puked it all back up again. Man that's a lot of good stuff. Around page 27, I just started scrolling through to look at the pictures because some of them are very lovely. I went to the layout section of this site to look for some of the board stuff, but only could find dano's original. I'm not sure if there is a verified section of layouts, mods, parts and stuff, but if there isn't, that could be a good thing to have.

I also think I'm going to have to try and put one of these together. I really liked the one that used two 12au7 tubes. I was thinking about making them more kind of like two pedals in one instead of one pedal. One footswitch would turn one on and another switch to activiate the next tube for more gain. I would like to only have 2 gains, one volume and one tone. Is that possible with this kind of setup? Then I also read in there somewhere that having a booster in there is a good idea too. So where is the best place for that to go? I was thinking of putting in a stratoblaster because the LB1 or 2 were said to be too muddy. Maybe even a stratoblaster before and after the circuit? Sheesh.

Also, I've only dealt with building a guytronix tube amp and a bunch of pedals, but they dont use 12v adapters. Where can I get one of these that good but also not very expensive, as I am poor.

Thanks  :icon_mrgreen: and sorry if this was all discussed. My mind is fried from the rest of this thread to comprehend the last few pages.

Here's a summary of some of the topics that inspired me to build this. 
http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary.pdf

Renegadrian's vero has been tested and known to work.  I also posted a PCB (but IMHO, a lot of extra work for such a small ckt. :icon_wink:)

Send us pics of your 'caster when you're done.   :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on September 05, 2008, 02:54:36 AM
Wow, I started reading that about three hours ago. Read, digested and puked it all back up again. Man that's a lot of good stuff. Around page 27, I just started scrolling through to look at the pictures because some of them are very lovely. I went to the layout section of this site to look for some of the board stuff, but only could find dano's original. I'm not sure if there is a verified section of layouts, mods, parts and stuff, but if there isn't, that could be a good thing to have.

I also think I'm going to have to try and put one of these together. I really liked the one that used two 12au7 tubes. I was thinking about making them more kind of like two pedals in one instead of one pedal. One footswitch would turn one on and another switch to activiate the next tube for more gain. I would like to only have 2 gains, one volume and one tone. Is that possible with this kind of setup? Then I also read in there somewhere that having a booster in there is a good idea too. So where is the best place for that to go? I was thinking of putting in a stratoblaster because the LB1 or 2 were said to be too muddy. Maybe even a stratoblaster before and after the circuit? Sheesh.

Also, I've only dealt with building a guytronix tube amp and a bunch of pedals, but they dont use 12v adapters. Where can I get one of these that good but also not very expensive, as I am poor.

Thanks  :icon_mrgreen: and sorry if this was all discussed. My mind is fried from the rest of this thread to comprehend the last few pages.

Here's a summary of some of the topics that inspired me to build this. 
http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary.pdf

Renegadrian's vero has been tested and known to work.  I also posted a PCB (but IMHO, a lot of extra work for such a small ckt. :icon_wink:)

Send us pics of your 'caster when you're done.   :)

In that summary on page 4 the Dual Valve Casters schematic 3. triode still missing a gridleak resistor.
http://www.diystompboxes.com/smfforum/index.php?topic=68759.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 05, 2008, 10:19:48 AM
Ah that .pdf file is wonderful. Thanks for answering everything to promptly.

I think I'm going to go with this twincaster schematic
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/Twincaster+rev+0_11.jpg.html

with the R1 pulldown on the second half, seeing as that one fellow had quite a bit of trouble. I am also thinking about adding a switch to cut in and out the second tube. What if I take a SPDT on/on switch, wire C3a to the middle lug, a wire on another lug going V2a where it usually connects then on the other lug, a wire between C3b and C4? I believe that would make it so in one switch direction it would make it like the regular valvecaster then the other way it would be a twincaster.

As for the booster, I'm a poor college student so ordering and building a bunch of different boosters will have to loose out to getting more grocerys  :'( So of the people that have put boosters before, what ones sound best? I play a strat and LP into my 2watt gilmour jr (which is a bit darker to begin with) with whatever effects inbetween.

Also, would it be a good idea to put an on/off switch in the back or something to get the tubes to warm up? Kind of like a standby?

Final question of the post - That fixed voltage regulator, is it necessary? It seems that adding that and then a heatsink would take up a lot of room (even though I'm planning on building it in a large enclosure anyway).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jimmy-H on September 05, 2008, 11:32:09 AM


A.  Also, would it be a good idea to put an on/off switch in the back or something to get the tubes to warm up? Kind of like a standby?


B. Final question of the post - That fixed voltage regulator, is it necessary? It seems that adding that and then a heatsink would take up a lot of room (even though I'm planning on building it in a large enclosure anyway).

A. I don't think it is necessary, no one did it anyway.

B. It's only necessary if you have a bad regulated and filtered power supply.
    I used an old printer (switching)power supply.
 success with your build! ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: served on September 06, 2008, 09:30:45 AM
I built mine. But i dont have a propper powersupply. I found one but output is 18V. How to make it work with 18V What has to be added?

I actually built Pepper Shredder, but its the same deal.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 06, 2008, 09:52:31 AM
I built mine. But i dont have a propper powersupply. I found one but output is 18V. How to make it work with 18V What has to be added?

I actually built Pepper Shredder, but its the same deal.

Use a 7812 like on the Twincaster circuit on the previous page of this thread to regulate your 18 volt input down to 12 volts. The 7812 has a maximum input voltage of 35 volts, so it should be fine
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 06, 2008, 01:04:46 PM
I built mine. But i dont have a propper powersupply. I found one but output is 18V. How to make it work with 18V What has to be added?

I actually built Pepper Shredder, but its the same deal.

Use a 7812 like on the Twincaster circuit on the previous page of this thread to regulate your 18 volt input down to 12 volts. The 7812 has a maximum input voltage of 35 volts, so it should be fine

So if I put a stratoblaster infront of it, which runs on 9 volts, should I use the 7812 infront of that to take it down the 12v adapter to 9v? Or can the stratoblaster run on 12v?

Here is the schem/parts I am using for it http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=64&Itemid=26

I know, I'm sorry this has nothing to do with the original purpose of the thread. I'm still in the process or drawing up how to breadboard will look, so hopefully you all can check that out for me too  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 06, 2008, 01:16:54 PM
I built mine. But i dont have a propper powersupply. I found one but output is 18V. How to make it work with 18V What has to be added?

I actually built Pepper Shredder, but its the same deal.

Use a 7812 like on the Twincaster circuit on the previous page of this thread to regulate your 18 volt input down to 12 volts. The 7812 has a maximum input voltage of 35 volts, so it should be fine

So if I put a stratoblaster infront of it, which runs on 9 volts, should I use the 7812 infront of that to take it down the 12v adapter to 9v? Or can the stratoblaster run on 12v?

Here is the schem/parts I am using for it http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=64&Itemid=26

I know, I'm sorry this has nothing to do with the original purpose of the thread. I'm still in the process or drawing up how to breadboard will look, so hopefully you all can check that out for me too  :icon_mrgreen:

I would guess the Stratoblaster should run on 12 volts, but as its a JFET you may need to re-bias it for 12 volts by changing R2. I think the process would be to build and test the SB at 9 volts, measure the voltage at the JFET's 'Drain', power it up at 12 volts and use a trimpot to replicate the voltage at the JET's 'Drain'.

Alternatively, I built a LPB into my second Valvecaster, and didn't do anything at all about the voltage change! So - it might work out just fine without doing a thing to it - just give a little more gain maybe........
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on September 06, 2008, 01:57:57 PM
In that summary on page 4 the Dual Valve Casters schematic 3. triode still missing a gridleak resistor.
http://www.diystompboxes.com/smfforum/index.php?topic=68759.0


Are you referring to this dialogue between ambulancevoice and Renegadrian?
http://www.diystompboxes.com/smfforum/index.php?topic=68759.msg550659#msg550659

I'll add this note to the summary.

Thanks!
-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on September 06, 2008, 04:37:06 PM
In that summary on page 4 the Dual Valve Casters schematic 3. triode still missing a gridleak resistor.
http://www.diystompboxes.com/smfforum/index.php?topic=68759.0


Are you referring to this dialogue between ambulancevoice and Renegadrian?
http://www.diystompboxes.com/smfforum/index.php?topic=68759.msg550659#msg550659

I'll add this note to the summary.

Thanks!
-bK
http://www.diystompboxes.com/smfforum/index.php?topic=68759.msg550722#msg550722
similar is true for FET gates: don`t let them float.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 06, 2008, 10:20:19 PM
(http://i246.photobucket.com/albums/gg114/mth5044/TSschem.jpg)

I added a DPDT switch in there between C3 and the new R1. Once you cut out the second tube, it should be exactly like a valvecaster right? Am I missing anything big here? Is there going to be an awful pop or something with the switch is engaged?

I'm going to add in a two color LED to the other side of the DPDT to show what tubes are being used. I found a 3 color LED while searching for the two color one. Is it bad if I want to build something just to use a three color LED   :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on September 06, 2008, 10:22:52 PM
Put the final connection of the switch before the last coupling "blocking" cap (C3).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 07, 2008, 12:23:45 AM
You mean the one right before the tone pot setup? If I did that, would that make 2 C3's in a row?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on September 07, 2008, 04:29:49 AM
yes, it will pop, and bytheway there are already 2 C3`s in that schematic ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on September 07, 2008, 05:16:07 AM
The names are not that important, but BTW yeah, it's a little bit confusing..

To put both C3 in series by switching will definitely pop out..

Anyway, are you sure of that wiring for your 1M R1(bis) resistor, right after the switch? Isn't that supposed to go from the plate to the ground?


Good idea about the LEDs, I'm planning to put some RGB automatically color changing in my tubes sockets.. Cool effect..  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 07, 2008, 10:40:22 AM
(http://i246.photobucket.com/albums/gg114/mth5044/TSschem-1.jpg)

based on my inferior knowledge of the recomendations, here is an updated schematic. I added a's and b's so hopefully it wont be as confusing, changed R1b and put the switch before C3b, although that doesnt make too much sense to me.

If there is no way to solve the popping part, I guess ill just build two valvecasters but use dual pots for the tone and volume. Pretty much the same thing I guess.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 07, 2008, 11:05:55 AM
So if I put a stratoblaster infront of it, which runs on 9 volts, should I use the 7812 infront of that to take it down the 12v adapter to 9v? Or can the stratoblaster run on 12v?

Here is the schem/parts I am using for it http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=64&Itemid=26

I know, I'm sorry this has nothing to do with the original purpose of the thread. I'm still in the process or drawing up how to breadboard will look, so hopefully you all can check that out for me too  :icon_mrgreen:

I would guess the Stratoblaster should run on 12 volts, but as its a JFET you may need to re-bias it for 12 volts by changing R2. I think the process would be to build and test the SB at 9 volts, measure the voltage at the JFET's 'Drain', power it up at 12 volts and use a trimpot to replicate the voltage at the JET's 'Drain'.

Alternatively, I built a LPB into my second Valvecaster, and didn't do anything at all about the voltage change! So - it might work out just fine without doing a thing to it - just give a little more gain maybe........

Either you could use a 9AU7 tube, which is the 9v version of the 12AU7...use a 7809 if you need a regulated v and run both fx at the standard 9v. I'd say 500mA or more as for the wall wart, try 300mA too but the more the better I believe.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on September 07, 2008, 11:09:54 AM
for less popping, add another 1M from the righthandside of C3a to ground.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 07, 2008, 11:14:16 AM
It might be best to uses a DPDT switch to isolate the second Valvecaster from the output.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 07, 2008, 11:24:40 PM
I think I'm just going to do it so that there are technically two valvecasters in one box, rather then going for a switchable twincaster. So it will go stratobooster -> valvecaster which when turned on will take to to the switch for the second valvecaster, and when off will take it to the out. That way when I want to go from 2 valvecasters to none, I'll only have to hit one switch. Then the second valvcaster switch will go to the out also. Kind of like this (sorry about the huge picture, my photoshop skills are lacking):
(http://i246.photobucket.com/albums/gg114/mth5044/switching.jpg)
VC1 and VC2 are valvecaster 1 and 2 and the two left sides of both switches reserved for LED indicators. Should I ground the 2nd lug on the third horizontal row on the VC1 switch? Usually not grounding something screws me over so I thought I'd ask.

\I'm also debating if I want to go with the dualgang volume and tone pots or do seperate ones for each. I like the dual gang for the less clutter, but I'm one for versitility, so maybe combining using two volumes and tones at the same time would be cool, like combining different tones and volumes on the middle switch of a les paul. I think I've got a pretty good layout design too, just need to see if pedalpartsplus can drill holes for tube sockets  :icon_rolleyes:

Thanks again for your help.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: served on September 08, 2008, 01:35:59 PM
Hey. Im starting to build that  circuit for fixed voltage. Is it wise to use one power supply and add two regulators to it? 12V and 9V? Is it wise to save some parts and put 7812 and 7809 parallel after 0.1uF and 470uF, but all that is after the regulator is independent, 7812 is with its own 3 caps to output and 7809 has its own?
I hope you ll understand what i mean.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 08, 2008, 01:49:08 PM
I didn't get what you mean...Do you want it to be powered at 9v or 12v?
You have to use either 7809 or 7812, depending on the choice above...
Else I don't see the need of 2 regulators...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: served on September 08, 2008, 05:13:44 PM
Ill build a powersupply for my pedals. All the transistor based pedals use 9V so i need it too. Guess it wont change anything if i put two 78xxs like i wanted. The point is, why do i have to waste 1x0.1uF and 1x470uF if i can keep thouse.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on September 09, 2008, 02:10:06 AM
In that summary on page 4 the Dual Valve Casters schematic 3. triode still missing a gridleak resistor.
http://www.diystompboxes.com/smfforum/index.php?topic=68759.0

Revised summary:

http://www.aronnelson.com/DIYFiles/up/12AU7-6111_Valve_Caster_Summary_Rev002.pdf
Includes the 'caster's 2nd 1Meg Resistor and the schematic and discussions re: the switch mod.

Thanks!  (:
-bK
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 09, 2008, 03:36:44 PM
Hmmm.... Ok - hi -  long time lurker - very rare post-er....

Here's the kind of problem you LOVE:
"Model-builder with lousy parts and barely passable solder skills seeks help with HUM."

First, apologies if I missed something in the 38+ pages, I have tried to read it all thoroughly.
I'm just hoping for some general advice before I scrap this one and re-build from scratch.

Massive hum problem - but the circuit boosts and distorts freaking GREAT.

Built the 7812 power regulator.
Caught a an ungrounded lug on a pot - that fixed some of the hum.
Caught a silly mistake, when I used a NP cap for C3 (the DC blocking cap, correct?)
BUT - that didn't seem to fix the problem at all.
Tried 3 12AU7s, 12AV7, 12AT7
Also, have tried 6v 500ma, 9v 200ma, 9v 500ma, 12v 500ma - all wallwarts, all hum. Higher voltage = more hum.
And OF COURSE, those are all QUALITY parts (sarcasm here), from various telephones, answering machines, baby monitors etc.

Here is where it all went off the tracks - I initially had my stupid DC wiring backwards (CANNOT get my mind around a negative tip. Call me wet behind the ears, I don't mind)  and so I'm wondering if I cooked something? The weird thing is, the circuit seems to work very well - just very very loud hum. Used to be as loud as the guitar signal, but the regulator and fixed grounding issue reduced the hum by about 50%
It's just on the verge of being usable now.
I'm not concerned about hiss, buzz, or any other noisy racket - just this loud HUM.

NOW - I'm getting about 4 VDC on the output! (surprised?)
So that means blocking cap (C3) and/or resistor (R3), right?! Or something else?
Could it be that every 1uF cap that I own (about 6, all salvage) doesn't work?
Could it be that my soldering skills demonstrate borderline dementia?
Did I mention the incredible quality of salvaged parts I'm using?
...actually, all but the 1uf were new parts... except the tube(s)... and the socket... and the jacks...

SO. Scrap it and start again (with newer parts) or is it salvagable?


Again, apologies if I shoulda started a new post or something, I do a LOT of reading, but not much posting. Prefer to keep my mouth shut when I don't know what I'm talking about.
Oh yeah, and btw everyone of you mofos completely rocks, this forum has been LIFE CHANGING for me. If it disappeared tomorrow I'd wander the streets aimlessly for weeks.


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 09, 2008, 03:42:56 PM
Hmmm.... Ok - hi -  long time lurker - very rare post-er....

Here's the kind of problem you LOVE:
"Model-builder with lousy parts and barely passable solder skills seeks help with HUM."

First, apologies if I missed something in the 38+ pages, I have tried to read it all thoroughly.
I'm just hoping for some general advice before I scrap this one and re-build from scratch.

Massive hum problem - but the circuit boosts and distorts freaking GREAT.

Built the 7812 power regulator.
Caught a an ungrounded lug on a pot - that fixed some of the hum.
Caught a silly mistake, when I used a NP cap for C3 (the DC blocking cap, correct?)
BUT - that didn't seem to fix the problem at all.
Tried 3 12AU7s, 12AV7, 12AT7
Also, have tried 6v 500ma, 9v 200ma, 9v 500ma, 12v 500ma - all wallwarts, all hum. Higher voltage = more hum.
And OF COURSE, those are all QUALITY parts (sarcasm here), from various telephones, answering machines, baby monitors etc.

Here is where it all went off the tracks - I initially had my stupid DC wiring backwards (CANNOT get my mind around a negative tip. Call me wet behind the ears, I don't mind)  and so I'm wondering if I cooked something? The weird thing is, the circuit seems to work very well - just very very loud hum. Used to be as loud as the guitar signal, but the regulator and fixed grounding issue reduced the hum by about 50%
It's just on the verge of being usable now.
I'm not concerned about hiss, buzz, or any other noisy racket - just this loud HUM.

NOW - I'm getting about 4 VDC on the output! (surprised?)
So that means blocking cap (C3) and/or resistor (R3), right?! Or something else?
Could it be that every 1uF cap that I own (about 6, all salvage) doesn't work?
Could it be that my soldering skills demonstrate borderline dementia?
Did I mention the incredible quality of salvaged parts I'm using?
...actually, all but the 1uf were new parts... except the tube(s)... and the socket... and the jacks...

SO. Scrap it and start again (with newer parts) or is it salvagable?


Again, apologies if I shoulda started a new post or something, I do a LOT of reading, but not much posting. Prefer to keep my mouth shut when I don't know what I'm talking about.
Oh yeah, and btw everyone of you mofos completely rocks, this forum has been LIFE CHANGING for me. If it disappeared tomorrow I'd wander the streets aimlessly for weeks.




Hi Chris! Test your voltages and post them here.

Here's mine, running at 12 volts:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 09, 2008, 03:44:36 PM
Oh yeah, and btw everyone of you mofos completely rocks, this forum has been LIFE CHANGING for me. If it disappeared tomorrow I'd wander the streets aimlessly for weeks.

we'd say it's better for you to stay, but even if you don't you gotta have your valvy up and running silently...

C3 (1µF) can be P or NP, I used them both...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 09, 2008, 05:37:10 PM
WOW. You guys are FAST.

OK, here's my numbers from 2 different wallwarts:

12v 500ma (meters at 17.5v)

1.   11.65
2.   -0.491
3.   0
4.   0
5.   13.42
6.   8.96
7.   -0.534
8.   0

9v 300ma (meters at 15v)

1.  9.86
2.  -0.335
3.  0
4.  0
5.  11.14
6.  8.02
7.  -0.330
8.  0

(pesky numbers - in my perfect world, all science is based on COLORS...)

Soooooo.... since my pin 1 is off the charts, am I to assume that my 220K (R2) is cooked, shorted, cold-jointed or otherwise?

Man, i was all proud thinking i'd troubleshot that C3 and now you blow it for me Renegadrian!!  :icon_redface:
I'da thought a blocking cap would need to only let stuff go one-way?
Welp, showing my ignorance here.
I've built about 40 projects, and I'd say my hit/miss ratio is a good 60/40!
- I can build models & puzzles real good, but I'm only so-so on the theory.

Thanks again for the quick replies, and thanks in advance for the help!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 09, 2008, 05:51:04 PM
12v 500ma (meters at 17.5v)

1.   11.65
2.   -0.491
3.   0
4.   0
5.   13.42
6.   8.96
7.   -0.534
8.   0

Soooooo.... since my pin 1 is off the charts, am I to assume that my 220K (R2) is cooked, shorted, cold-jointed or otherwise?

Thanks again for the quick replies, and thanks in advance for the help!

Yup, it's pin 1 that's the problem as you correctly identifed! Check the resistor with your meter for ohmage/continuity. And shorts, cold-joints or otherwise!

All the other voltages look good, but your 12 volts DC looks like its actually 13.42 volts, judging from pin 5. I think that may still be within the heater tolerance, but it would be worth you checking that out on a 12AU7 data sheet. It might be overheating the heater! Ideally the heater wants 12.6 volts, though 12 volts would be fine.

Good luck!

Rick

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 09, 2008, 06:23:06 PM
WOW. You guys are FAST.

Man, i was all proud thinking i'd troubleshot that C3 and now you blow it for me Renegadrian!!  :icon_redface:
I'da thought a blocking cap would need to only let stuff go one-way?

Thanks again for the quick replies, and thanks in advance for the help!

Look where the question comes from...
It's a P in the schem but a NP in the wiring layout---
(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCaster.gif)
(http://www.beavisaudio.com/Projects/ValveCaster/MatsuminValveCasterWiring.gif)

And read that I've been thru the same doubt...
http://www.diystompboxes.com/smfforum/index.php?topic=63479.180

So no, that's not the issue...I've used both and don't find such a difference...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 09, 2008, 06:47:51 PM
Hey man, post some sound clips when you get it all worked out. I love listening to these thing.

I can't wait to get mine up and running. Two valvecaster and a booster, but I can't quite deside on the booster. I was going to do the stratoblaster, but someone said the SHO was good infront of it. I read they were noisy though. Any other easy, simple, CLEAN booster that have been tested good with this thing?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 09, 2008, 06:52:14 PM
Hey man, post some sound clips when you get it all worked out. I love listening to these thing.

I can't wait to get mine up and running. Two valvecaster and a booster, but I can't quite deside on the booster. I was going to do the stratoblaster, but someone said the SHO was good infront of it. I read they were noisy though. Any other easy, simple, CLEAN booster that have been tested good with this thing?

PentaBoost (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0)
Title: Where do you generally have your Valvecaster volume set?
Post by: frequencycentral on September 09, 2008, 06:57:31 PM
Where do you generally have your Valvecaster "Volume" control set?

If you're anything like me, then you like gain, dirt and crunch.

That means setting the Gain pot high and the Volume pot low - right?

So, if the volume pot is set to 25% that's 75K of serial resistance cutting away at your treble.

Jeez - no wonder this circuit has the reputation of sounding a little 'dark'!

When I set up the plate resistors on my Vibracaster (http://www.diystompboxes.com/smfforum/index.php?topic=70160.0) I set it up for unity gain between the bypassed and effected signals - it doesn't suffer from 'darkness' like the Valvecaster does - no volume control > no serial resistance dragging away the highs.

I'm gonna bridge my 100K Volume pot with a 10K resistor, it will mean I can't use the Valvecaster as a clean boost - but hey, I'll just build me a PentaBoost (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0) instead.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 09, 2008, 07:42:03 PM
Man, did you just write an add for your pentaboost? I imagined it being like a child in a cereal commercial.  :icon_lol:

I will have to check into your pentaboost. Thanks.

edit: oh man, just read about the pentaboost. I think it will do lovely in the same box with two valvecasters. Have you tried it as a boost before the 12au7 type valvecasters?

Plus now I can tell people its an 'all tube' unit.  :icon_mrgreen:

how do you mount them buggers anyway? I was going to put the 12AU7's out the top, so I would like to have the little guy sticking out there to.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 09, 2008, 08:00:07 PM
Man, did you just write an add for your pentaboost? I imagined it being like a child in a cereal commercial.  :icon_lol:

I will have to check into your pentaboost. Thanks.

Q:"How do you keep your teeth so shiny and white?"

A: "I only use 'PentaBoost' (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0) when I brush!"


or

"Take two bottles into the shower? Shampoo and conditioner? Not me - I just take 'PentaBoost' (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0)....."

or

"Tired of dull, lifeless guitar riffs.......?"

You get the picture! Always room for humour and shameless self-promotion around here...........

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 09, 2008, 09:29:25 PM
Look where the question comes from...
It's a P in the schem but a NP in the wiring layout---

And read that I've been thru the same doubt...
http://www.diystompboxes.com/smfforum/index.php?topic=63479.180

So no, that's not the issue...I've used both and don't find such a difference...

Hah - Adriano, I wish I was that astute and could blame the discrepancy for my mix-up, but really i just wrote out a quick manifest and started slapping it together based on the layout... I didn't reference the actual schematic until I started having problems! ::) Hey, like I said, I'm a model-builder...
---
SO, I had to break for dinner and all that (wives really like it when you put down the iron and the guitar) - but I did go back over my stuff, and checked R2, and my solder joints.

The resistor metered ok, the connections are all iffy though. Since it was a first-time build for me, i used an old socket I got from Mendelson's here in Dayton, and the thing was crusty and weird and sacrifice-able ... in retrospect, this sort of logic is probably 90% of my problems...
Also, I crammed all my parts onto the backside of that socket as close as I could get them for the sake of being compact. That might not be good either.

So, geez, you know, I could keep beating this thing to death, but it's like, EIGHT freakin PARTS?!
So I'm gonna start a new one from scratch tonight - now that i've got a 'proof of concept' build done, I'll use a NEW socket, and everything else NEW too!!!

Thank you Rick and Adriano, I really appreciate the help, and I'll try to get some kind of sound clips posted after I get the new one done!

many thanks -


Title: .
Post by: Renegadrian on September 10, 2008, 04:29:21 AM
Right Chris, post your results when done, ok?!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on September 10, 2008, 11:41:01 PM
I don't know if you guys remember but I built mine then the gain pot stopped working. Turns out the actual pot went bad...never had that happen. O well on a simple circuit like this that I understand it wasn't too hard to track it down.

Stock circuit minus a 33nF input cap... I don't find this circuit dark at all. Though I always have liked and have a slightly bright stock tone. Nice boost/OD.

(http://img152.imageshack.us/img152/529/dscf0129bi9.jpg)

(http://img152.imageshack.us/img152/4789/dscf0126zl7.jpg)

A great little circuit, great fun to play with.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: cheeb on September 11, 2008, 12:07:27 AM
Looks great!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on September 11, 2008, 01:54:01 AM
Great font choice man, looks professional  8)

Where can I get some of those knobs from? I've got a pedal underway that they'd be perfect for... thanks!
Title: knobs
Post by: Renegadrian on September 11, 2008, 05:13:30 AM
Andrew, I know Banzai got them ---------->(http://www.banzaieffects.com/files/images_thumbnail/t_18777.gif) (http://www.banzaieffects.com/Neutrik-RE-AN-knob-pr-18777.html)
They are german based, I don't know if your trusty retailer got them...Else go buy them thru Banzai...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on September 11, 2008, 05:22:15 AM
Looks great! Is that an etched design?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 11, 2008, 08:10:26 AM
That looks really good, congratulations.

When you say minus the 33nf cap, what one are you talking about? The input is a 47, did you cut it down to 33 or just leave it out all together?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on September 11, 2008, 12:22:16 PM
Great font choice man, looks professional  8)

Where can I get some of those knobs from? I've got a pedal underway that they'd be perfect for... thanks!
I got mine from Effects Connection...50cents!! Mad cheap...only issue is they are push on. I had to drill mine out a bit and they were still quite snug on my solid shaft.

I just used decals on my pedal.

I made the input 33nF
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 11, 2008, 01:49:14 PM
Sorry but I can't resist this:
Mad cheap...only issue is they are push on. I had to drill mine out a bit and they were still quite snug on my solid shaft.
...yeah, i've had some girlfriends like that ! uh, it's been quite a few years though, sadly...

But I digress -
Hello again -  I'm back after throwing another valvecaster together -
This time, I used a NEW socket, NO SALVAGED parts, and I put everything but the tube/socket on perfboard, so there was no risk of weird crosstalk/shorting/interference etc.
I am also running power through a perfboarded 7812 regulator circuit.

Overall, the sound quality is much better - where it was passable cool overdrive before, it is getting really sick good now. The noise floor seems to be considerably lower as well.

BUT - I am still getting that lousy HUM, and am still seeing 4vdc on the signal output!!!
Also, something else weird... i'll get to that in a second.

Here are numbers: (this time I'll include pin9 - i dunno why i neglected that before, i guess because it's NC)

1.   3.87 (9.5)
2.   -0.266
3.   0  (.9)
4.   0
5.   11.03
6.   4.9
7.   -0.219
8.   0
9.   5.68
(parenthesis explained below)

Also NOTE, I left out the TONE pot and cap (c4), left off VOL pot, was trying to simplify as much as possible.
I had left out the GAIN pot as well, but then i saw those weird numbers in parenthesis up there, and thought the omission might have something to do with it.
So I dropped in a 100k,  and now I can sweep it from the low setttings on pin 1 & 3 above to the high settings in parenthesis.
The control audibly works as expected.
So I dunno what that is all about. Those high numbers are way off the mark, right? Should that gain pot be doing that?


If I run the AMP gain on 0 it all sounds typical of a stompbox app, but if I turn the AMP gain up AT ALL, the hum seems to get exponentially louder...
so, what the ?!, am I missing something here, or making some noob/fundemental mistake, or am i just tweaked?

I think I am correct in blaming the hum on the 4v on the signal output, right?!  ???

ONE LAST BIG THING:

...remember i told you that i wired the power on my first build backwards (cuz i'm a dingus)  -
Could I/Did I damage each of the 5 tubes I plugged in trying to get that running?  :icon_sad:
Is it possible now that my tubes are all wonky, and that's where all the hum is coming from?




... as for those knobs, and those build pics.... sheesh, i wish i could build stuff that clean.
I'm usually happy if sound comes out at all.  As for the knobs, I say again, Mendelson's in Dayton, Ohio, i pickup up a good sized handful of those same knobs, i think at 10cents each - problem is, that place is a mammoth warehouse, and there is very little organization, so i might never find them again!



Title: valvy
Post by: Renegadrian on September 11, 2008, 02:05:44 PM
Sorry but I can't resist this:
Mad cheap...only issue is they are push on. I had to drill mine out a bit and they were still quite snug on my solid shaft.
...yeah, i've had some girlfriends like that ! uh, it's been quite a few years though, sadly...
WOAH, THAT MADE ME LAUGH!!!  :icon_lol:


But I digress -
Hello again -  I'm back after throwing another valvecaster together -
This time, I used a NEW socket, NO SALVAGED parts, and I put everything but the tube/socket on perfboard, so there was no risk of weird crosstalk/shorting/interference etc.
I am also running power through a perfboarded 7812 regulator circuit.

Overall, the sound quality is much better - where it was passable cool overdrive before, it is getting really sick good now. The noise floor seems to be considerably lower as well.

BUT - I am still getting that lousy HUM, and am still seeing 4vdc on the signal output!!!
Also, something else weird... i'll get to that in a second.
SOUNDS GOOD!!!

IF YOU RUN PIN 3 TO GROUND YOU GET MAX GAIN OMITTING THE POT...OR DID I GO WRONG?!

ONE LAST BIG THING:

...remember i told you that i wired the power on my first build backwards (cuz i'm a dingus)  -
Could I/Did I damage each of the 5 tubes I plugged in trying to get that running?  :icon_sad:
Is it possible now that my tubes are all wonky, and that's where all the hum is coming from?

PIN 4 AND 5 ARE THE HEATERS, BUT THEY CAN BE USED BOTH WAYS, SO NO MATTER WHICH DIRECTION YOU USED...

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on September 11, 2008, 02:08:44 PM
But I digress -
Hello again -  I'm back after throwing another valvecaster together -

Pin 6 seems a little low.

The circuit wont work without the gain pot. Directly earthing pin 3 would give maximum gain without a pot though.

The hum could be a badly filtered/regulated power supply - try the circuit with a 9 volt battery and see if the hum goes away. If it does, it's the powers upply causing the hum.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 11, 2008, 03:02:00 PM

Yep, I had originally run Pin 3 to ground, for simplest part setup - i knew that would give me either a min or max gain, which was fine for testing purposes.
 
:icon_idea: wow, actually try it with a battery! I'm a total idiot. Why didn't I think of that?!
yeah, as i said, my wallwarts are TOP quality, ;D from whatever random useless electronics sources...

(20 minutes later)
uh, well, scouring the house has turned up 3 batteries- 8.5v, 2.5v, and 7.8v ... needless to say, none of them are having any luck lighting that piece of shi... uh, shiny glass tube...
So, i guess i gotta run out for some good ol' cheap Odd Lots batteries! Nothing but the best for me baby!


Another question though: i AM using that 7812 circuit, for regulation... Should that be doing something, or is it just doing 'regulation' but not actually helping screen any crappy noise from my lousy PS?
(nice run-on question there)


And a quick word: I already mentioned how important this forum is to me, but I gotta also say, that even though i'm having trouble with this build, it is my favorite so far.
I've built a couple TS clones, Phase 45, Tremulous Lune, Orange Squeezer, Pulsar, a bunch of little booster/distorts (opamp and transistor), and a whole bunch of stuff that hasn't worked at all.
My previous fave was the Tillman, for low parts count, ease of build, and satisfying results. Just enough to hit my Marshall a leeetle beet harder on the front end, you know?
I really really wanna get the Tillman and this Valvecaster together, I think it could be LOVE, L U V.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 11, 2008, 03:31:25 PM
Might I recommend the Visual Sound 1 Spot adapter for this project? They have a 12v version. Can handle 1500mA  :icon_eek: and is ~$20. I have three of the 9v one and they are totally silent and have not died yet. I plan on getting one when I get around to this project. Just my 0.02.
Title: VALVECASTER
Post by: Renegadrian on September 11, 2008, 03:59:03 PM
Chris, the 7812 is mainly for regulation, you should put some filtering too - as suggested in the previous pages, a 100µF el.cap between + and - on the DC jack filters a good amount of s**t.

Quote
I really really wanna get the Tillman and this Valvecaster together, I think it could be LOVE, L U V.

I tried the two togheter - I think you are going to like them coupled...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on September 11, 2008, 04:04:53 PM
edit
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 11, 2008, 05:56:42 PM
Ok, still haven't run out for 9v batts yet, but going to after supper -

Tried the 100uf electro on the PS both before, and after regulator, didn't really do anything. Maybe took away a teensy hiss.
Tried higher values out of frustration  :icon_confused: - some of those seemed to really muddy up the hum, but still didn't get rid of it.

:icon_idea: I had a thought that maybe that 100k/220k pair were too wimpy (eh, remember, i'm very short on theory), so I pulled them and found a couple cool carbon-comp resistors that are bigger. Might be the same wattage though, i dunno. They seemed to improve the hum to an extent, and seemed to reduce the voltage on the signal output by about a volt.
But what is weird though too, the gain control, when rolled back the gain goes down and the hum goes UP.... not an aural illusion either, it's REALLY noticable, esp with the guitar quiet.


The Visual Sound 1 spot - yes, that seems a good deal at $20, i may just invest in one of those.
I DO have a Boss PSA, but it's enclosed in my pain-in-the-butt pedal board ... I might just have to break it out tonight... once i do though, i'll never get the backside back on that thing. Oh well, it really needs a good tweaking anyway. My mechanical engineering is about as good as my electrical.


But, can anyone else confirm for me whether they are getting voltage on the signal output (FOUR VOLTS?!), am I an idiot here, that just can't be right, can it? Am I gonna cook my amp?

I promise to reward everyone for their time with some cheescake pix and more dumb questions!  ;D







Title: VALVECASTER
Post by: Renegadrian on September 11, 2008, 06:24:34 PM
You could dub it LUXURY CASTER when you're done, right?!  :icon_wink:
Man, I like your band...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 11, 2008, 10:50:22 PM
Ok, i got batteries, but the device doesn't want to run off of them.
The filaments light up - and with one of the batteries i could hear the faintest of sounds, but basically nothing.

So, does that point to a serious error somewhere or something? Did I get an old revision of the schematic or something? I've looked at that PDF of all the compiled stuff from everyone's posts, and I didn't see anything in there that looked out of place.

I just dunno what is going on. If I could just get rid of that hum it would be insane.

Eh - Glad you like the band Adriano - sadly, June was the last month it existed for all intensive purposes.... See, the singer.... eh, it's a long story, but not such a great guy, and after 3 years for me, 2 for the drummer, and FIVE for the bass player, well, everyone's had enough.
The band basically imploded a couple months ago, though I think the singer is going to try to get some schlubs to fill in for some October dates.   I'd be happy to give you copies of the albums, or access to download them, if you're interested. I guess just shoot me your email in a private message?

did get a lot of GREAT rock photos from playing in that band - i will miss that.
I got a new thing starting up though - waaaay different, but i'm gonna make a buck at it this time around.

eehhhhhhh........ but VOLTAGE on my signal out?  -  do i need to explore 'coupling/decoupling' or something?
I guess my next step is to try to sub out each of my components until maybe i hit something that was faulty or ?
oh, and get out the Boss PS and see if that works.

any other suggestions are appreciated.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 19, 2008, 01:38:53 PM

soorry on the long delay - weird week in Dayton, we were a disaster area! :o  ...remnants of Ike...

OK - the BOSS PSA power supply has eliminated the BAD HUM that I was experiencing, and I think put it into the realm of 'totally usable' now -  ;D
I haven't swapped that input cap, but I think it sounds great on humbuckers or single coils so far! Can't believe how much crunch you can get out of it, I might look into one of those 'clean boost' mods listed in the PDF, or maybe on the next build.

Voltage on the signal output is down to 2.5v now, which still seems absurd to me, but i don't know where to start troubleshooting, or if that is even trouble. I read a post somewhere that said something like "try metering your pedals output for DC, you'll be surprised!" but it didn't really offer much by way of answers - just implied bad components/construction and/or design...

So, I guess I'll have to look into buying a few DECENT power supplies, and get rid of some of the garbage i've been using.

Success on this has inspired me to revisit some old projects I never got running - a Boss FA1, Jade Fuzz, and and Uglyface... we'll see if I get anywhere on those. If I do, I've got abot 20 others to revist after that!

thanks for the help!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on September 19, 2008, 02:15:44 PM
OK - the BOSS PSA power supply has eliminated the BAD HUM that I was experiencing, and I think put it into the realm of 'totally usable' now -  Grin

GREAT to hear that you got it working!     ;D
Got pics or sound clips of the build?

I also use the BOSS PSA120T, 200mA, it's a great little power supply provides good clean power.  Much better than it's little brother ACA120, 200mA which puts out a lot of hummmm.  (They are little work horses, had them for over 15  years or so and they all work fine)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 19, 2008, 03:09:32 PM

Well, it's all still all alligatored all to heck, perfboarded the parts, and no outboard stuff yet, it's all just on my little "test-bed" i "built"   ::) dunno how i'm gonna mount the tube socket somewhere, it's pc mount i think...

... but i'll get a couple pics of that mess cuz you guys will like to see it, and then i'll box it up and bring it up to the computer for some sound bites. Might be a minute (=days), but i'll get that much done!

The bonus is: I actually built TWO, because i thought the first was F@#$@#$'d, and since i've narrowed it done to my awful p-supplies, that means i'll have both in the bag at once!!

Thank you everyone for your help and encouragement, even though I'm just a 'paint-by-numbers' builder, (or 'model builder' as I like to call it - y'know, like 1/72 scale Spitfires? - I build 2/1 scale distortions  ;D) ... even though I'm only at that level, I still have learned TONS OF STUFF from this FORUM and from the builds.

Every time I finish something and it works, it's like winning a trophy or something!!! And just think of the money I'm saving, I probably ONLY have like $1500 invested in the 4 or 5 reliable pedals I've built ! :icon_eek:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 19, 2008, 06:02:15 PM
Congrats on the build. You should put cascade them and tell us what you think.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on September 19, 2008, 07:09:05 PM
Thank you everyone for your help and encouragement, even though I'm just a 'paint-by-numbers' builder, (or 'model builder' as I like to call it - y'know, like 1/72 scale Spitfires? - I build 2/1 scale distortions  ;D) ... even though I'm only at that level, I still have learned TONS OF STUFF from this FORUM and from the builds.

Every time I finish something and it works, it's like winning a trophy or something!!! And just think of the money I'm saving, I probably ONLY have like $1500 invested in the 4 or 5 reliable pedals I've built ! :icon_eek:

Eheh, hey model builder!!!  :icon_lol:
Glad you have a good valvy...Now it just needs a decent box...Hope you enjoied building it, after all that's what the DIY is about...Have fun, build nice pedals and learn something new...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 19, 2008, 08:26:45 PM
eh, cascading, and soundclips, and running with a tillman pre, etc., will be forthcoming...
for now, feast your eyes... on the mess... that IS... my workbench....
 :icon_twisted: muhahaHAHAHA  :'( (sob.)


(http://www.wrightfield.com/stompbox/P9199776.JPG)

naw, it does me ok. I could probly keep it a little bit cleaner... :icon_neutral:
can you spot the quote testbed unquote?

here's the current state of the 'real good' one... i forgot to get a closeup of the other.
also, i already pulled my i/o wires and stuff because i started messing with that fuzz jade again -
that other little piece of perf i think is an LPB1 that I need to box up.
(http://www.wrightfield.com/stompbox/P9199777.JPG)

and speaking of boxes, I have NO problems there... except for WHICH to CHOOSE?
(http://www.wrightfield.com/stompbox/P9199778.JPG)

Lastly, a couple 'cheesecake' shots for ya - a shelf of stuff i've built and boxed, that actually works - and then a big pic of some of the other pedals i own...

(http://www.wrightfield.com/stompbox/P9199781.JPG)
(http://www.wrightfield.com/stompbox/P9199782.JPG)
(http://www.wrightfield.com/stompbox/P9199783.JPG)


sorry for all the blur, and hope reveling in the pron isn't too off topic here... i just can't help myself.

sound clips RSN, i promise!
Title: Dr. Stein?!
Post by: Renegadrian on September 19, 2008, 09:16:41 PM
for now, feast your eyes... on the mess... that IS... my workbench....
 :icon_twisted: muhahaHAHAHA  :'( (sob.)

(http://www.wrightfield.com/stompbox/P9199776.JPG)


It reminds me of this...
(http://bp1.blogger.com/_k9i5BR1aNww/R7ZdDnFDRQI/AAAAAAAAADc/xqnE6cuaVDc/s400/Helloween+-+Dr.+Stein+-+front.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: c.wright on September 19, 2008, 10:13:53 PM
Hah - yep Adriano, that's a good comparison - my creations are generally monstrosities that don't last too long in the light of day!
Ah yes, Helloween... did you somehow sense my metal roots?

btw, i added some little tags to those pics to help make sense of things.

I'm off to try to box up a tube or two! 
This afternoon I managed to get SOUND out of my Jade Fuzz, so I'm on a roll.
Wish me luck...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DiamondDog on September 20, 2008, 12:32:16 AM
Question:

Those who are using a 78xx regulator, I'd be interested in your readings. The notes for the regulators say Vin should be 3v over your Vout. If you want 9v out, put 12v in. Is that holding true?

Build 'feelings':

Over the last week I've built and playing with two AU7 vavlecasters. The second I built is a clean boost (R2 100K, R3 47K, C1 .022uF, no tone stack) and is in the chain before the second, which is as per Dano's on-the-socket layout. Both are running at 9v at the moment.

I've left the boost on all the time, and the second is used as a switchable overdrive. I tried a Rangemaster in front of the clean boost, where it just distorted everything. However, put between the two, it pushes the 'overdrive' valvecaster pleasantly.

If you are breadboarding a twincaster, try a booster between the two "circuit-ettes". It may suit your needs- then it may not!  ;)

I might try a vibracaster next... See you over in that thread.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on September 20, 2008, 10:59:27 AM
!!!!!!!!!!!!! You have one of the morley oilcan do-dads! Oh man. Plus plenty of other stuff. Luckly its all jambled around in a workspace, so if someone breaks into your house, they wont realize theres thousands of dollars crammed in there. Geez man you should move that stuff to a volt or something.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Franky on September 21, 2008, 05:48:26 PM
Yeehaa! A friend of mine gave me a whole bunch of tubes, mostly 12AU7, he found an incredible stock (about 200 tubes) in his garage, some of them might be dead but I found some good references (Telefunken)..

There are also a lot of PCF, ECF, PCL tubes, I don't know if these are usable for low (or high) voltage amplifier circuits, but that is so good, I'm ready to build a bunch of tube pedals..  :icon_biggrin: :icon_cool:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on September 22, 2008, 06:51:04 AM
Yeehaa! A friend of mine gave me a whole bunch of tubes, mostly 12AU7, he found an incredible stock (about 200 tubes) in his garage, some of them might be dead but I found some good references (Telefunken)..

There are also a lot of PCF, ECF, PCL tubes, I don't know if these are usable for low (or high) voltage amplifier circuits, but that is so good, I'm ready to build a bunch of tube pedals..  :icon_biggrin: :icon_cool:

Awesome!  Looking forward to seeing some builds soon!   :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 06, 2008, 02:29:53 PM
Hi all,

I just finished building a Twincaster with switchable second tube stage.
My problem is that the pedal is VERY quiet. Even with only one tube stage the output signal is MUCH lower than the input signal. I've checked the circuit a few times. When I turn up the Gain the signal gets distorted , but the output signal is always very low.
I tried running it at 9 and 12 Volts. No change. Any ideas?

Thanks
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SirElwood on October 06, 2008, 02:31:44 PM
Any ideas?

Post your voltages.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 06, 2008, 02:40:02 PM
Voltages with pedal running at 12V

PIN1 9,14
PIN2 -0,44
PIN3 0,006V
PIN4 0,00V
pIN5 12,33V
PIN6 10,07V
PIN7 -0,38V
PIN8 0V
PIN9 6,1V

Or should I better post voltages at 9V ?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 06, 2008, 02:46:35 PM
Here's mine (again):

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

Your pin 1 voltage is way too high - are you sure you have the corect value resistor?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 06, 2008, 02:58:00 PM
Pin 6 is also a little off. Thats both your plate voltages off.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 06, 2008, 03:07:30 PM
Hm, checked R1. Its 999 Ohm.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 06, 2008, 03:11:01 PM
Hm, checked R1. Its 999 Ohm.


Yeah, that's a 1K resistor you have there, not a 1M. Like having a volume control at the front end turned almost all the way down.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 06, 2008, 03:11:55 PM
Sorry its 999 K ... I used the right one but my post was wrong
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 06, 2008, 03:43:00 PM
Check the value of the resistors at pins 1 and 6 too.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 06, 2008, 04:26:37 PM
R2 220K
R3 100K

Seems to be ok.
How muck boost of your input signal do you have? Maybe I expect too much?
When Gain is a litle above 3/4 then the output level is equal to the input level (but overdriven as it should be)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 07, 2008, 02:37:28 AM
It should have plenty of gain and boost. Set the gain to maximum and the volume to unity with the bypassed signal - measure the ohmage of readings between the volume control lugs. I'll compare yours to mine. Probably best to debug the two valvecaster circuits seperately
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 12, 2008, 05:06:44 PM
Ok, I think I found out the problem. I debugged both stages separately. Both work fine. The tone stack I added was the problem. Without it all voltages seem to be normal and the pedal has enough boost ;-)
Maybe I find another tonestack which works.
Title: ...
Post by: Renegadrian on October 12, 2008, 05:21:53 PM
Smiler, glad you finally got that one working...So is my layout verified??
Impressions on that one or sound samples??
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on October 12, 2008, 05:22:13 PM
Ok, I think I found out the problem. I debugged both stages separately. Both work fine. The tone stack I added was the problem. Without it all voltages seem to be normal and the pedal has enough boost ;-)
Maybe I find another tonestack which works.
Tonestacks seriously suck gain. If you want one you'll need a recovery or boost stage.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 12, 2008, 05:46:12 PM
Ok, I think I found out the problem. I debugged both stages separately. Both work fine. The tone stack I added was the problem. Without it all voltages seem to be normal and the pedal has enough boost ;-)
Maybe I find another tonestack which works.

You can increase the volume of a Valvecaster by changing R3 to 220K or higher, if you do this for both stages it might be enough to compensate for the tonestack volume loss.

EDIT: You should get even more volume by increasing R2 as well, 470K maybe.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 12, 2008, 05:57:14 PM
@Renegadrian:

Not 100% Yet ;-) I completely rebuilded the whole pedal to find this error. Tested the first and then the second stage. After adding the tone stack the pedal becomes very quiet and all voltages become strange. Don't know why. I'm testing at the moment, but your Twincaster board-layout (Twincaster rev 0_11.jpg) looks good. My first build was an enhanched version of your layout (with switchable second tube stage and tone stack). My current build has no board. The tons of wires make it more difficult to debug ;) By the way: Why do you use electrolytics for C3 ?

@kurtlives & frequency central:

I've heard that it sucks gain. Anyway I'm confused about the voltages when using the tone stack. PIN2 has about 4V without and about 9V with tone stack. Will try using 220K for R3 tomorrow.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 12, 2008, 06:02:08 PM
Anyway I'm confused about the voltages when using the tone stack. PIN2 has about 4V without and about 9V with tone stack. Will try using 220K for R3 tomorrow.

Are you sure you have a DC blocking cap between the tonestack and pin 2 - that would be C1 in the schematic.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on October 12, 2008, 06:09:58 PM
@Renegadrian:

 Why do you use electrolytics for C3 ?

http://www.diystompboxes.com/smfforum/index.php?topic=63479.msg568630#msg568630

See here at page 39  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 12, 2008, 06:12:02 PM
Are you sure you have a DC blocking cap between the tonestack and pin 2 - that would be C1 in the schematic.

Yes, 47nF...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 12, 2008, 06:14:59 PM
Are you sure you have a DC blocking cap between the tonestack and pin 2 - that would be C1 in the schematic.

Yes, 47nF...

Maybe you should have one either side of the tonestack.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 12, 2008, 06:17:26 PM
Hey Adriano - how's it hanging? Another Valvy question and we all come out of the woodwork.......

.......did you like the Red Star Drive (http://www.diystompboxes.com/smfforum/index.php?topic=71350.0)?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on October 12, 2008, 07:47:52 PM
yeah man, you're right, I've been a bit busy those last days...
I love all of your tube layouts, the latest too, while you know I am a high gain fan...
Still I like some low gainers, like the pentaboost...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 13, 2008, 01:48:17 PM
Adding a 47nF DC blocking cap didn't work. Still 9V on PIN 1 and low output. I didn't try changing R3 and R2 yet but would it really increase volume and NOT gain?
Someone here said he build up a valvecaster with tone stack. Does anyone know a (passive) tonestack that doesn't suck volume? If not I will build up a regular Twincaster with tone control only. Have six holes in the enclosure, but there will be a way to close them with a label.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 13, 2008, 02:30:27 PM
Adding a 47nF DC blocking cap didn't work. Still 9V on PIN 1 and low output. I didn't try changing R3 and R2 yet but would it really increase volume and NOT gain?
Someone here said he build up a valvecaster with tone stack. Does anyone know a (passive) tonestack that doesn't suck volume? If not I will build up a regular Twincaster with tone control only. Have six holes in the enclosure, but there will be a way to close them with a label.

In a standard Valvecaster, increasing R2 will increase the gain, increasing R3 will increase the volume.

If you can't find a suitable tonestack (I don't know of one that doesn't suck gain), you could add the Vibracaster (http://www.diystompboxes.com/smfforum/index.php?topic=70160.0) tremolo mod to your twincaster, that would add two more knobs, rate and depth.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SirElwood on October 13, 2008, 04:26:04 PM
Here is a tone control that has quite low insertion loss. Change capacitor values if nessesary.
(http://www.tg-music.com/Gibson%20GA-30RVT%20Tone.gif)

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 13, 2008, 04:54:21 PM
Hm, looks nice but I don't have any of this 6111 here :(

BUT I removed the tone stack, replaced it with standard tone+volume pots and FINALLY got a nice idea :)

I will add a second tone and volume control for the second tube! Have 3 free pins left on the 3PDT that enables the second stage. So either the first or the second tone+vol controls are enabled depending on the second tube stage being on or off  ;D

Only have to buy pots & stuff.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on October 13, 2008, 05:35:23 PM
Here is a tone control that has quite low insertion loss. Change capacitor values if nessesary.
(http://www.tg-music.com/Gibson%20GA-30RVT%20Tone.gif)



no resistor from grid to ground?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on October 13, 2008, 06:12:11 PM
Hm, looks nice but I don't have any of this 6111 here :(

Should work identically with 12AU7.  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SirElwood on October 13, 2008, 06:27:06 PM
no resistor from grid to ground?

That is an error on my drawing. :icon_redface: But that tone part is correct.

And yes, it will work with 12AU7 as well.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 22, 2008, 11:44:30 AM
Hi :)

Finally got my Twincaster working! I added second tone and volume controls. Switch 1 is a 3PDT, so I labeled it SW1a and SW1b. There is also an LED connected to it (not shown here). So I have independent tone and volume depending on having tube B active or not.

If someone will also build it like this, here you are:

(http://i386.photobucket.com/albums/oo302/Smiler/TSschem-1_switchable.jpg)

Based on mth5044's Schematic.

I will post pictures of the whole pedal when I've finished the enclosure-design :)

EDIT: corrected SW1a position
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Krinor on October 22, 2008, 05:52:40 PM
Wow, it seems like I've missed the last 25 pages or so... I guess I've been busy building Valvecasters or something.
Here's a little video of my latest which is going out to a hopefully happy customer tomorrow. It's the 11th Valvecaster I've made.
People love these things. This is a stock version. Only thing I've done is to put a 3pdt switch in there. It's on (but bypassed) once you plug in the power and a guitar cable, so you don't need to wait for the tube to heat up once you push that button.

http://www.youtube.com/watch?v=3cMqYlhSQ8c

Okay, okay I'm sorry about the crappy playing and that blue LED. I didn't have any other colours. Honestly.  :icon_rolleyes:


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on October 23, 2008, 12:56:23 PM
Okay, okay I'm sorry about the crappy playing and that blue LED. I didn't have any other colours. Honestly.  :icon_rolleyes:

I use two blue ones :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on October 24, 2008, 01:33:30 PM
Blue LEDs and polished metal enclosures look sooooo gooooood. Better then anyother color IMO.

Looks good.
Title: Valvecaster
Post by: Renegadrian on October 27, 2008, 07:42:23 PM
Just a little update for the knowledge or the DIY community...

I just finished my 7th Valvy, using a 9AU7 (and a 7809).
Works good and there are no big differences. Easy to find that tube on evilBay for little $$$
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on November 07, 2008, 03:02:15 PM
Just another experience: Especially if someone will build a Valvecaster with two tubes, USE A 7812 !
I had problems with lots of hum. With two tubes -> more hum. Just builded up a little circuit with 7812 regulator and two (not too small) elelectrolytics. Works great!! Just shhhhh and no HUMMMMMMMM ;-)

Even my so called 12V "regulated power supply" was a little crappy. Now I've found a cheap 18V 650mA power supply which works.
Title: 8th Valvy
Post by: Renegadrian on November 07, 2008, 06:00:58 PM
Here's my 8th Valvy - I found this little box, actually designed to hold coins, and I went - Would it be crazy to build a Valvy inside one of those? Hell yeah - ok, I have to do it!!!

So here it is!!! I dedicated it to my gone too soon daddy, who left us ten years ago. It was a rainy november day, just like today...
I know he'd appreciate...

(http://img136.imageshack.us/img136/6564/valvy008nw4.th.jpg) (http://img136.imageshack.us/my.php?image=valvy008nw4.jpg)(http://img136.imageshack.us/images/thpix.gif) (http://g.imageshack.us/thpix.php)
Title: Re: 8th Valvy
Post by: frequencycentral on November 07, 2008, 06:11:36 PM
Here's my 8th Valvy - I found this little box, actually designed to hold coins, and I went - Would it be crazy to build a Valvy inside one of those? Hell yeah - ok, I have to do it!!!

So here it is!!! I dedicated it to my gone too soon daddy, who left us ten years ago. It was a rainy november day, just like today...
I know he'd appreciate...

(http://img136.imageshack.us/img136/6564/valvy008nw4.th.jpg) (http://img136.imageshack.us/my.php?image=valvy008nw4.jpg)(http://img136.imageshack.us/images/thpix.gif) (http://g.imageshack.us/thpix.php)

Man that makes me sad - but 8 >>> you are the Valvecaster Master!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: robizz on November 08, 2008, 03:54:17 AM
anyone has made a mod increasing the beavis audio valvecaster gain?

(my valvecaster runs with 12 volt power supply!)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on November 08, 2008, 05:33:55 PM
anyone has made a mod increasing the beavis audio valvecaster gain?

(my valvecaster runs with 12 volt power supply!)

Have a look at this: http://www.diystompboxes.com/smfforum/index.php?topic=71864.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on November 09, 2008, 08:04:23 PM
Now Tube Town have a Valvecaster varient: http://www.tube-town.net/diy/lov/lov03-bananabooster.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mitzrecords on November 11, 2008, 08:01:03 PM
hhmmm I just built one. but there is a little radio frequencies. other than that, it sounds really good.

I checked GEO debugging page and followed the instruction and mine is true bypass with 3pdt switch,

sorry dumb question but for the shielding, mine enclosure have some vents like little holes. does this effect?

sorry i dunno what else to do..
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on November 13, 2008, 11:48:18 PM
Well, I'm finally getting around to building the damn thing (two valvecasters and a 5672 boost in one box), and the design I'm going to implement has room for a bunch of switches, probably 6 TOPS! Reading the PDF, there are a lot of mods, so I thought I'd ask.

What is your favorite mod(s)?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on November 15, 2008, 07:50:49 AM
hhmmm I just built one. but there is a little radio frequencies. other than that, it sounds really good.

I checked GEO debugging page and followed the instruction and mine is true bypass with 3pdt switch,

sorry dumb question but for the shielding, mine enclosure have some vents like little holes. does this effect?

sorry i dunno what else to do..

I don't think that the holes have a big influence... Try to connect all ground wires to a single point (input or output jack) if you don't have already. Another thing you can try is to connect the case to ground (some signal and DC jacks are isolated and maybe there is no connection from ground to the case).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Cursor on November 15, 2008, 09:07:17 AM
I realised I still hadn't used the NOS American (CBS) 12U7 that Brett kindly hooked me up with about 18 months ago.

So last night I threw together a Valvecaster - and WOW. I can see what everyone's raving about. A definate "authority" to the sound, with gorgeous breakup when I crank the gain. My stock Tele loves it, but a hot Dimarzio humbucker really brings out the best. A Shin Ei FY-2 in front of it sounds b*****d heavy but removes the dynamics completely.

Now to breadboard LPB-1, Sparkle Boost (any other boost suggestions?) and a few others and find the best booster to put in the box.

I'm using a decent 12V wallwart and have no noise issues. I used a 100Kb pot for the gain control but otherwise built stock. The caps in the diagram are perfect for me (I used green beasties), not too bright or dark.

Love it!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on November 15, 2008, 09:10:46 AM
Now to breadboard LPB-1, Sparkle Boost (any other boost suggestions?) and a few others and find the best booster to put in the box.

PentaBoost (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0) - keep it all tube!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Cursor on November 15, 2008, 09:25:54 AM
PentaBoost (http://www.diystompboxes.com/smfforum/index.php?topic=70524.0) - keep it all tube!

- Hmm, there's a thought. If only I had subminis. I could trawl through the tubes box for other space charge pentodes, but I believe I'm completely out of sockets now.

I'm tempted to nick the ECH83 triode-heptode preamp and PSU out of my hybrid amp (http://www.coldcity.com/index.php/hybrid-guitar-amp/). I wonder how the 12U7 Valvecaster would handle a B+ of 20V. Datasheet suggests it'd be OK, but I'm not sure I even want the headroom; I really like the sound as is.

Also, solid-state would definately fit in the box  ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Br4d13y on November 16, 2008, 11:23:41 PM
i was wondering if it could be easily changed to run a 12at7? i don't have time to read through all the pages, so i just want to see if it is posible as this is the only of the 12a*7 series tubes i have now.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on November 17, 2008, 07:00:42 AM
It will probably run just like it is with a 12at7. The only thing is you migght get massive ugly distortion, but maybe not. You will definitely get more gain, as 1t7 is higher gain than au7, but IIRC it has higher Ip, I don't know if that will affect this circuit or not.

Might as well try it for now and then just put in the 12au7 later.

Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Br4d13y on November 17, 2008, 11:16:07 AM
ok, i will just go with that ;D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on November 17, 2008, 03:34:24 PM
I did try a 12at7 in it in the past - no big differences...but I'd stay with the u's...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on November 17, 2008, 10:11:44 PM
Cant find it now... What are the "clean" mods? I remeber it involved the plate resistors.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: andrew_k on November 17, 2008, 10:42:27 PM
Cant find it now... What are the "clean" mods? I remeber it involved the plate resistors.

Halve them.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: squallc on November 25, 2008, 10:29:42 AM
 :icon_lol: Hi guys,
I have built this matsumin valve caster, it's sound good for me. But, i want to add more Gain, how to do that. And i feel some compressed sound if i turn the gain pot to max. I want to increased the gain to get a "picking: sound.
Need your help, thanks.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on November 25, 2008, 12:19:42 PM
:icon_lol: Hi guys,
I have built this matsumin valve caster, it's sound good for me. But, i want to add more Gain, how to do that. And i feel some compressed sound if i turn the gain pot to max. I want to increased the gain to get a "picking: sound.
Need your help, thanks.

Have a look at this: http://www.diystompboxes.com/smfforum/index.php?topic=71864.0

It's not quite a Valvecaster, but based on it. And it needs verifying.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on November 25, 2008, 04:03:26 PM
:icon_lol: Hi guys,
I have built this matsumin valve caster, it's sound good for me. But, i want to add more Gain, how to do that. And i feel some compressed sound if i turn the gain pot to max. I want to increased the gain to get a "picking: sound.
Need your help, thanks.
You could try a bypass cap on the gain pot. Try 0.68mF for a bit more bite and gain or 22mF for a nice linear boost.
Title: Valvecaster
Post by: Renegadrian on November 28, 2008, 07:34:54 AM
Another experiment report for the records...
I tried to put in a 6021 (submini dual triode tube) powering the heaters thru a 7806 (it must receive 6.3 V)
The pins follow the 6111 schematic you can find in the first pages

It works but the sound it's not good at all...Guess I have to breadboard it and find the mandatory tweakings that could make this tube shine!!! Not for now, though...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on November 28, 2008, 09:30:04 PM
http://www.etsy.com/view_listing.php?ref=cat2_galley_9&listing_id=17111340

$139...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on November 28, 2008, 10:11:17 PM
Looks pretty lame, for $140 I would expect it as least painted. The description is pretty funny.

Wonder who's vero layout he used ::)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on November 29, 2008, 02:33:31 AM
did he show up here yet?
http://www.happyrobotmusic.co.uk/info.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Zben3129 on November 29, 2008, 12:20:24 PM
I like the fact that that pedal wont work for half the people considering he put in a 12v reg and is saying to use a 12v supply. Anyone who tries to use a 12v regulated supply is gonna get nothing  :icon_eek:



Zach
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: drk on November 29, 2008, 04:51:11 PM
I like the fact that that pedal wont work for half the people considering he put in a 12v reg and is saying to use a 12v supply. Anyone who tries to use a 12v regulated supply is gonna get nothing  :icon_eek:



Zach

though exactly the same when i read it :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on November 29, 2008, 09:52:34 PM
Looks pretty lame, for $140 I would expect it as least painted. The description is pretty funny.

Wonder who's vero layout he used ::)

  This is from his website.
 

Many thanks and respect to Andrew Carrell for providing such good layouts which some of these pedals are based on.

If you want to know more about making your own guitar pedals please visit www.diystompboxes.com

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on November 29, 2008, 10:40:01 PM
Andy never made a vero layout for the Valvy though.
Title: Re: Valvecaster
Post by: Jered on November 29, 2008, 11:05:48 PM
Another experiment report for the records...
I tried to put in a 6021 (submini dual triode tube) powering the heaters thru a 7806 (it must receive 6.3 V)
The pins follow the 6111 schematic you can find in the first pages

It works but the sound it's not good at all...Guess I have to breadboard it and find the mandatory tweakings that could make this tube shine!!! Not for now, though...

  Here you go Adriano. The first schem is straight high gain. The second is med/high gain with over the top gain switching. Also added an EQ by-pass switch to allow the full tone without any loss.
  Sounds good at 18 volts but increase the voltage and it becomes more amp like, especially above 24 volts. With some minor tweaks it works at 12 volts, but at 12 volts it is hard to get the palm muting chunk you want with high gain.
(http://img.photobucket.com/albums/v316/jered1011/HighGain6021.jpg)
(http://img.photobucket.com/albums/v316/jered1011/MediumandUltraHighGain6021.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on November 29, 2008, 11:20:49 PM
Can you explain the 470pF caps going from plate to cathode on some tubes? Shave off some highs?

Also whats the point of the 2M2 and that cap (cant read value) from the plate to grid? Seen this before in some Dumble designs, some form of NFB?


I like your use of filters throughout, original design?
Title: Jered
Post by: Renegadrian on November 30, 2008, 06:24:23 AM
Jered, you're the man!  :icon_wink: Guess I'll have to send you some more Rome souvenirs...
THX again for the tubes and for your kindness. And  for those schems too! I'll try the first next week!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: guitarman89 on November 30, 2008, 07:05:57 AM
scusa renegadrian io sono di carpineto romano e vengo tutti i giorni a roma perchč studio alla sapienza, ma queste mini valvole le posso trovare anche nella capitale??  :icon_lol:
Title: 6021
Post by: Renegadrian on November 30, 2008, 11:37:58 AM
Check this out,it should be correct...I'll try it for sure, Jered, I surely look for high gain and got a 6021 handy waiting to be heated...
EDIT: I inverted the order of the 2 res at the input (pulldown comes after) - I believe it's the same thing, isn't it?
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=37853&g2_serialNumber=1)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on November 30, 2008, 07:45:29 PM
BUILD REPORT
Unfortunately this thing doesn't seem to work...Gotta check it better tomorrow, maybe I went wrong on the soldering or the layout has something wrong (pls check it!)
The tube lights on, and that's ok...it gets its 6v thru the 7806...But no sound at all... :icon_cry:
I run it at 12V, I know 18 or 24 would give more headroom, but only got a regular wall wart around, so I put 12V
I guess it should give some sound anyway...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: squallc on December 01, 2008, 10:32:18 AM
:icon_lol: Hi guys,
I have built this matsumin valve caster, it's sound good for me. But, i want to add more Gain, how to do that. And i feel some compressed sound if i turn the gain pot to max. I want to increased the gain to get a "picking: sound.
Need your help, thanks.
You could try a bypass cap on the gain pot. Try 0.68mF for a bit more bite and gain or 22mF for a nice linear boost.
Thanks, bypass Cap will add some gain, but it is on the first stage, how about the second stage of 12 AU7? i'm sure it will generate more harsh/fuzz sound?not an overdrive. Actually, i need some bite sound/ more picking sound with a super sensitive.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 01, 2008, 10:30:15 PM
  Layout looks ok. Maybe it won't work at 12 volts. I'll put it back on the breadboard and give it a try at 12 volts. I'll report back.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on December 01, 2008, 11:49:32 PM
  OK just breadboarded it at 12 volts and it works fine. Loses a little headroom at 12 volts but still sounds real good.
Title: 6021vero layout VERIFIED
Post by: Renegadrian on December 02, 2008, 09:17:23 AM
Jered, I checked my vero again - The layout is correct, I just made a late night error at building, I soldered a cap in the wrong tracks...obviously the signal path was broken and then...NO SOUND!!!
Made the right connection and VOILA' IT WORKS!
I get a Valvecaster-like gain at 12V, I believe 18 or 24 surely give more headroom.
A good power filtering is MANDATORY.

THX again for your work.   :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on December 02, 2008, 09:22:44 AM
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=37853&g2_serialNumber=3)
Title: Valvecaster
Post by: Renegadrian on December 02, 2008, 11:22:05 AM
Back on the standard Valvy - a friend reported me the following mods he made...

R2 (orig. 220k) 56k to avoid distortion at min gain.
R3 (orig. 100k) 560k he gets a nicer gain, in his words...

gotta try them...just two res. swap...

He also puts a 1µF cap at the 7812 between ground and Vout, in place of the 100µF between Vin and ground.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: served on December 08, 2008, 09:23:01 AM
Some how, i cant find the power regulator anymore... Im using 2 transistors one for 12V and the other one for 9V. There are punch on caps and that all. I got a schematic somewhere, but i cant find it anymore. Some one?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: guitarman89 on December 08, 2008, 10:18:14 AM
Another experiment report for the records...
I tried to put in a 6021 (submini dual triode tube) powering the heaters thru a 7806 (it must receive 6.3 V)
The pins follow the 6111 schematic you can find in the first pages

It works but the sound it's not good at all...Guess I have to breadboard it and find the mandatory tweakings that could make this tube shine!!! Not for now, though...

  Here you go Adriano. The first schem is straight high gain. The second is med/high gain with over the top gain switching. Also added an EQ by-pass switch to allow the full tone without any loss.
  Sounds good at 18 volts but increase the voltage and it becomes more amp like, especially above 24 volts. With some minor tweaks it works at 12 volts, but at 12 volts it is hard to get the palm muting chunk you want with high gain.
(http://img.photobucket.com/albums/v316/jered1011/HighGain6021.jpg)
(http://img.photobucket.com/albums/v316/jered1011/MediumandUltraHighGain6021.jpg)

is it possible to use the second schematic like a little preamp at low voltage (18/24 V)??
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Smiler on December 19, 2008, 10:24:30 AM
FINALLY put everything together!!  ::)

After a while my Twincaster is finished. Got some pictures for you:

(http://i386.photobucket.com/albums/oo302/Smiler/IMG_3228.jpg)

(http://i386.photobucket.com/albums/oo302/Smiler/IMG_3229.jpg)

(http://i386.photobucket.com/albums/oo302/Smiler/IMG_3221.jpg)

More Pictures: http://s386.photobucket.com/albums/oo302/Smiler/

Enjoy and thanks for your help finding errors!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on December 19, 2008, 10:45:46 AM
It looks so nice! Congrats on this one!!! (http://forum.ubuntu-it.org/Smileys/xmas-smileys-new/grin.gif) (http://forum.ubuntu-it.org/Smileys/xmas-smileys-new/good.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on December 22, 2008, 11:51:27 AM
That's really Smiler.

Although you might want to watch out when changing the knob settings.. if the tubes get hot.

Ouch.  :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: puretube on December 22, 2008, 01:39:49 PM
Tube-Builders do it "Sticking Out"!

 :icon_cool:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on December 22, 2008, 01:50:33 PM
(http://forum.ubuntu-it.org/Smileys/xmas-smileys-new/rotfl.gif)



my green machines...

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38072&g2_serialNumber=1)
Title: Triode Triode
Post by: Renegadrian on December 24, 2008, 06:41:59 AM
Triode Triode

I made a layout last month and built it, but it didn't work at first, I debugged it yesterday, and well, it was just a track break I forgot - now it works so good and it surely has a good amount of gain!!!
I read some posts about it at page 9, but it's not clear if the design is by brett, and the schem doesn't report its creator...

So brett, if it's your work, let me know and I'll add proper credits in my layout,ok?

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38098&g2_serialNumber=2)
Title: Re: Triode Triode
Post by: frequencycentral on December 24, 2008, 07:55:22 AM
Triode Triode

I made a layout last month and built it, but it didn't work at first, I debugged it yesterday, and well, it was just a track break I forgot - now it works so good and it surely has a good amount of gain!!!
I read some posts about it at page 9, but it's not clear if the design is by brett, and the schem doesn't report its creator...

So brett, if it's your work, let me know and I'll add proper credits in my layout,ok?

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38098&g2_serialNumber=2)

I don't see a schematic for that on page 9 - looks like its disappeared! Can you post one? How does it compare with the stock Valvy?

I really liked your Vibracaster soundclips by the way Adriano.
Title: triode triode
Post by: Renegadrian on December 24, 2008, 08:06:20 AM
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38100&g2_serialNumber=1)

this is the schematic I used - just changed the uper parts, but that's just the power section - actually it hasn't got a 7812 but I think I'll put one in - for now it's just a vero with "flying wires"

It's not that far away from the Valvy...maybe a little more gain...I'd suggest you to try it, after all it's just a simple circuit...

Still working on the V2, but the trimpot you suggested me didn't work...

I am glad you liked my Vibracaster and its samples - thx for such a good circuit!

I am raising my glass of Nero d'Avola wine at that tube s..t!!! yeah!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on December 24, 2008, 08:18:07 AM
Looks identical to the Valvy but with larger value caps, and gain set to maximum. Probably more bottom end, and the 500k volume pot will make the maximum volue louder (maybe?) Too similar for me to build really.

I've just cleared my breadboard of my last project (Multimode Filter), so I'm gonna have a play with "V2" again over the holiday.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: runmikeyrun on December 25, 2008, 01:39:11 AM
Well after reading all 45 pages i have spent several hours soldering up a twincaster on vero (thanks Renegadrian!).  I'll have to pick up some tube sockets on Saturday am and then fiddle with r2/r3 values but it's otherwise pretty ready to be fired up.  I dug out my rca 12au7 and philips JAN 12at7 so i can see what this thing can do.  I'll be going for a high gain application on bass guitar.  Hope this sounds good on bass!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on December 25, 2008, 04:18:47 AM
Right, post the final results then!!!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 703224796 on January 03, 2009, 04:12:39 AM
I have a question about the pedal sale situation:  I am planning on building one of these, and selling it on Ebay for a few extra bucks (college loans suck, don't they?! :icon_confused:).  Is there any legal implications that I must know before doing this?  I feel like matsumin is going to sue me or something :o...lol....I just want to make sure I don't do anything stupid.  Thanks
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 03, 2009, 04:51:06 AM
Build it for yourself - don't sell it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: squallc on January 06, 2009, 06:33:32 PM
Hi there, I have built this Original Mitsumin Valvecaster, actually, i have some loud HUM sound, is it probably because of power supply? how to clean the power supply?
Need your suggest to clean this HUM.
Thanks 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on January 06, 2009, 06:39:06 PM
Hi there, I have built this Original Mitsumin Valvecaster, actually, i have some loud HUM sound, is it probably because of power supply? how to clean the power supply?
Need your suggest to clean this HUM.
Thanks 

You see that 'Triode Triode' schematic a few posts above your post? Build the voltage regulator part of that circuit and apply it to the plates of your Valvecaster.  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 06, 2009, 06:57:43 PM
Rick, it should be quieter than the 100µF alone on the dc jack, am I right?!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on January 06, 2009, 07:04:09 PM
Rick, it should be quieter than the 100µF alone on the dc jack, am I right?!

Quiet and more stable - unregulated '12 volt' supplies can vary wildly upwards from 12 volts. You wouldn't want 17 volts across the heater right? That's a neat little circuit. However, I just use a single cap - but my power supply is very stable.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 06, 2009, 07:12:25 PM
Yeah, I meant the 7812 and the cap on the dc jack...As I always do...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on January 08, 2009, 01:32:57 AM
Aw man! I'm getting frustrated here!
I tried this circuit out (original valve caster) with a non center tapped ecc85 before and ran it at 6.3 volts and it worked out fine.
Had some problems with it lighting up like a lightbulb when running on 9/12 volts (go figgure)-

Now however i've got some brand new ecc82's and they light up like lightbulbs when i try to run the heaters on 9/12 volts in SERIES.. I do use pin 4 and 5 for power and I meassure about 8 ohms across pin 4 and 5 to pin 9 and about 16 ohms across pins 4 and 5 so it makes sense.. except it doesent work (works way to well rather).
I use a regulated powersupply that i've checked a dozen of times.

I guess the only thing that could do this would be if pin 9 was grounded but it's not.. I've checked and checked again.. acctualy concidering drilling the socket for pin 9 out.

 ??? :icon_cry: :icon_cry: :icon_cry:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sonbone on January 08, 2009, 02:12:01 AM
I built a subcaster with 6111 tube using a V+ of 24 volts.  More headroom for pedal steel and Telecaster guitar with high output pickups.  I was looking for a clean sound to warm up the sound of my transistor amps. Tried several voltages on the breadboard, 12V, 18V, 24V and 33V.  Liked 24V the best for my application.  For the power supply I built a separate "brick" with 2 mouser trannies.  Mounted 5 pin DIN connectors to the power supply and the pedal and use standard midi cable for power transmission.  I think this setup might also work well with the previous schematics using 6021 submini tubes, but I don't have any and I haven't tried it.  Links to pics and schematic below.  Sorry but the gut shot is a little out of focus, but you can get the idea.

(http://img150.imageshack.us/img150/9761/24vsubcasterko5.th.gif) (http://img150.imageshack.us/my.php?image=24vsubcasterko5.gif)

(http://img234.imageshack.us/img234/9610/6111minitubegutnp1.th.jpg) (http://img234.imageshack.us/my.php?image=6111minitubegutnp1.jpg)

(http://img150.imageshack.us/img150/3668/6111minitubeboostlh4.th.gif) (http://img150.imageshack.us/my.php?image=6111minitubeboostlh4.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 08, 2009, 06:19:58 AM
Albot, I tried several different brands, every tube has its own light, going from a dim light to a bright light...So that shouldn't be a problem...I wonder why it doesn't work... ???



Sonbone, great work!!! I like your pedal, how's its sound?!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on January 08, 2009, 07:30:32 AM
  Sonbone, I agree, at about 20-22 volts you can start to hear what you would hope to hear from a vacuum tube circuit, if that makes any sense.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on January 08, 2009, 11:08:00 AM
Mine light up with a bright glowing white/yellow light.. I think im simply cursed!  :icon_evil:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Albot on January 08, 2009, 11:40:26 AM
So when i try to run only the heaters out of the circuit, 12 volts make the entire heater pipe glow orange since i've never seen that in pictures i guess it's bad.
Oh im so worried, irritated and frustrated! dont wanna break my new tubes!
Especally since I wouldn't learn anything from it except that im cursed.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 08, 2009, 11:59:37 AM
Albot, the 12au7 is made to run the heaters at 12V - so don't worry about that...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: sonbone on January 08, 2009, 04:52:13 PM
This pedal sounds really smooth, adds quite a bit of warm to transistor amp.  My computer with recorder is down right now, so I can't record samples.  I have a version on my breadboard with both cathodes bypassed with 22uf caps and biased with 1.5K resistors.  Gain control is through 500K pot between stages. It's similar to Real McTube.  It has a much more aggressive sound since there isn't any negative feedback going to the cathodes.  I like the circuit on the breadboard better with my stratocaster.  Also sounds much better at 22V and above.  Two reasons I settled on 24V.  (1) 7824 voltage regulator in power supply filters better than just using rectifier and caps (which gives me about 33V with 24V ac transformer). (2) To me the circuit sounds best with volume control as close to wide open as possible.  Above 24V the gain is so much that I really have to cut back the volume.  I tried a voltage divider at output, as in Real McTube, but I don't really like that any better than just cutting back the volume.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: intricatecode on January 12, 2009, 09:17:16 PM
hi guys  ;D

been following this thread for a long time but only recently registered here so i could post. Anyway here are some pics of my dual valvecaster:

http://picasaweb.google.com/lh/photo/7TEglQRTtORH-XrPrAMSbA?feat=directlink (http://picasaweb.google.com/lh/photo/7TEglQRTtORH-XrPrAMSbA?feat=directlink)
http://picasaweb.google.com/lh/photo/8nKdyLj9lwrciY7mb7vyUw?feat=directlink (http://picasaweb.google.com/lh/photo/8nKdyLj9lwrciY7mb7vyUw?feat=directlink)

I'm running it at 18V and i've placed a jfet buffer before each valvecaster stage. I have loads and loads of questions for you guys but for now i leave only the pics  :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 12, 2009, 09:25:55 PM
Hi there - I think I've seen it before - did you post it on other forums?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: intricatecode on January 12, 2009, 10:26:26 PM
Only at forumusica.com it's a portuguese forum for musicians someone else did a valvecaster there too but nowhere else that i can recall.

I have to buy some more 12au7's so i can experiment with this circuit some more, there are loads of things that i'd like to try, using jfets as a ccs instead of the plate resistor, using voltage pumps so i can get more voltage using a standard 9v power supply, etc... I have loads of questions for all you guys but i have to gather my stuff before i go berserk here  ;D

I will post some ideas i have in the next few days.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on January 13, 2009, 02:18:36 AM
Only at forumusica.com it's a portuguese forum for musicians someone else did a valvecaster there too but nowhere else that i can recall.

I have to buy some more 12au7's so i can experiment with this circuit some more, there are loads of things that i'd like to try, using jfets as a ccs instead of the plate resistor, using voltage pumps so i can get more voltage using a standard 9v power supply, etc... I have loads of questions for all you guys but i have to gather my stuff before i go berserk here  ;D

I will post some ideas i have in the next few days.

Well I've used a PNP BJT as a CCS with a similar circuit, the effect is a little brighter and with some more gain:

http://www.diystompboxes.com/smfforum/index.php?topic=71864.0

Here I am using a MAX1044 voltage pump for higher voltage, but its an amp not a pedal - I'm still developing this idea. I will try it with a pedal eventually too:

http://www.diystompboxes.com/smfforum/index.php?topic=73317.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 13, 2009, 10:08:47 AM
The 12AU7 really opens up once you get past 20V DC. At 12V DC I find the sound is way to dark/bassy and compressed.

My latest 12AU7 tube project uses a B+ of 38V DC. Still want to try out something in the 60V DC - 100V DC range to see what it sounds like.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: castillogm on January 13, 2009, 12:00:05 PM
Hello y'all!

I'm gonna spend my very first post on this thread since I've read all the 40+ pages of this amazing project.  It's very inspiring to see how a simple tube and a few resistors and caps can make that chunky distortion that I've been looking for a long time. 

I think I'm on that guitarist 'phase' where you're looking for pure tone and eventually get rid of those multieffects that only give you headaches while trying to adjust a ton of parameters... Now I'm trying to keep things simple, and fortunately for my quest a pair of 12at7 tubes came into my hands while I was buying some stuff from stewmac.com ("tubes? why do you need a tube? I dunno... for 10 bucks maybe will look cool in some steampunk stuff").

So now I'm waiting for those tubes and very anxious to start the project.  I'd really like to thank you all for sharing your knowledge and I hope that in the next few weeks you'll see my creation.

Regards,

Mario (mexico)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: intricatecode on January 13, 2009, 06:14:11 PM
Only at forumusica.com it's a portuguese forum for musicians someone else did a valvecaster there too but nowhere else that i can recall.

I have to buy some more 12au7's so i can experiment with this circuit some more, there are loads of things that i'd like to try, using jfets as a ccs instead of the plate resistor, using voltage pumps so i can get more voltage using a standard 9v power supply, etc... I have loads of questions for all you guys but i have to gather my stuff before i go berserk here  ;D

I will post some ideas i have in the next few days.

Well I've used a PNP BJT as a CCS with a similar circuit, the effect is a little brighter and with some more gain:

http://www.diystompboxes.com/smfforum/index.php?topic=71864.0

Here I am using a MAX1044 voltage pump for higher voltage, but its an amp not a pedal - I'm still developing this idea. I will try it with a pedal eventually too:

http://www.diystompboxes.com/smfforum/index.php?topic=73317.0

I've been following your work for quite sometime ;) but i only have a bunch of j201 around so i went looking about on the web if it was possible to use a jfet as a constant current source and aparently it is possible but i haven't tested it yet because in the meanwhile i have been using my double valvecaster full time on my pedalboard  ;D recording an album and playing it live.

Anyway here are a couple of links i found about CCS and tubes:

http://headwize.com/projects/cavalli2_prj.php (http://headwize.com/projects/cavalli2_prj.php)  has an explanation on using jfets, mosfets, and other types of ccs with tubes
http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&no=211 (http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&no=211) comparison of performance of different kinds of ccs

I haven't come around to really explore the math and concept behind the usage of ccs's with the tubes but what appealed to me about using jfets is that you can do it with a lot less parts than with a bjt even though the performance may be less. From what i've read just tying the gate and source of a jfet will give you a ccs with the value of the jfets Ids. What this value should be to use with the valvecaster i haven't had the time to work out so far.

Regarding the voltage pumps i read somewhere that the icl7660 is more robust than the  MAX1044 and is pin compatible and that the icl7660scpa version is less prone to give an audible "wine" when using it as a voltage pump.

I'm relatively new to electronics and diy effects pedals the double valvecaster was my first build so i still have a lot to learn about triodes fortunately this forum has been a great help so far and pages like this one http://www.aikenamps.com/CommonCathode.htm (http://www.aikenamps.com/CommonCathode.htm) have  helped a lot about understanding how all of it works.

Right now i have to find the time to work out all the math in my head and review all my electronics concepts (it's been a few years since high school) so i can hopefully contribute with some ideas to  :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on January 13, 2009, 06:36:56 PM

Regarding the voltage pumps i read somewhere that the icl7660 is more robust than the  MAX1044 and is pin compatible and that the icl7660scpa version is less prone to give an audible "wine" when using it as a voltage pump.


It's the other way aound - the 1044 has a frequency boost feature which the 7660 lacks. I have both in my stocks, and a MAX on the bradboard at the moment - I'll pull it and replace it with a 7660 and see if the whine is bad.

Thanks for the links!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: intricatecode on January 14, 2009, 06:37:25 PM
Well I was feeling kind of bummed today and so i thought about getting out my trusted soldering iron and try out some of the ideas i had about using a J201 as a CCS on the valvecaster to clear my head.

Here's what i came up with:

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38340&g2_serialNumber=1)

I used it on the last triode stage of the valvecaster running it at 18v and it made quite an audible diference.

The first thing i did was to use the J201 with the source and gate tied but it didn't work so well, so i thought about soldering a 20k pot between source and gate and wiggle it about to see if it made any difference. I found a sweet spot and  using a switch compared the sound between the CCS and the standard 100k resistor and the CCS was quite a bit louder  ;D

So then i measured the voltage difference on pin 6 between using the CCS and the 100k resistor, with the CCS i got about 15v and with the 100k resistor it was about 10v. I measured the resistance value of the pot and it was about 65 ohms, it stayed quite a bit louder up until 1k and after that started to get progressively quieter. When i went under the 65 ohms it started  to sound weird and also quieter.

So there you have it folks  :icon_mrgreen: now i'm happy as a camper with a louder valvecaster prototype on my hands and a couple of more ideas up my sleeve.

Please try it and tell me if this works for you too.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on January 14, 2009, 08:14:53 PM
Only 5 posts and you come up revolutioning the Valvy... :icon_eek: Seems a good mod to do...After all, just a j201 and a res....
Title: EF86 Preamp
Post by: Renegadrian on January 15, 2009, 06:05:13 PM
Gonna try out this one, I guess it won't be a distortion unit but a good clean preamp

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38344&g2_serialNumber=2)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on January 15, 2009, 08:13:57 PM
Where did you get this idea from?

I really doubt an EF86 pentode will run on 12V DC.
Title: EF86 Preamp
Post by: Renegadrian on January 15, 2009, 08:26:27 PM
I just did the vero, I found the schem googling around (don't remember where)
I uploaded in my directory, just click --->HERE (http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38346&g2_serialNumber=1)
Title: Re: EF86 Preamp
Post by: SirElwood on January 15, 2009, 10:45:36 PM
I just did the vero, I found the schem googling around (don't remember where)

Hi!

Looks very familiar. I draw that schematic and post it in reply #478 (page 24) in this topic. If you found that schematic somewhere else than my page (http://www.tg-music.com) please tell me.

http://www.tg-music.com/EF86.pdf
Title: EF86 Preamp
Post by: Renegadrian on January 16, 2009, 05:18:36 AM
Hi Elwood - pls PM or write here your complete name, so I can credit you on my layout (also check if I made any errors...) - I don't remember where I did find it, maybe you could try googling it and see for yourself - as you can see it's not the PDF you linked but a cut image of just the schematic.

How does it sound BTW?!
Title: Re: EF86 Preamp
Post by: SirElwood on January 16, 2009, 05:40:45 PM
Hi Elwood - pls PM or write here your complete name, so I can credit you on my layout (also check if I made any errors...) - I don't remember where I did find it, maybe you could try googling it and see for yourself - as you can see it's not the PDF you linked but a cut image of just the schematic.

I had no luck with google. Need to try harder. ;D

How does it sound BTW?!

It's been five or so years when I build that. But if my memory serves me right, it's very clean, warm and maybe a bit "hi-fi". It does get better with higher voltage and good tube. I used old Tesla EF86. Alot better than new electro haromonix. Svetlana EF86 might be good new tube.
Title: EF86 Preamp
Post by: Renegadrian on January 16, 2009, 06:02:07 PM
Yeah, I read that altough there are some guitar amp schems around, the EF86 is well known for being clean, so it's mainly used on phono preamps.

edit - I got 3 nos ef86, so they should sound good...I'll try it soon...
Title: Some Q's about the Valvy
Post by: Renegadrian on January 20, 2009, 08:42:12 AM
I was reading some docs, and this always helpful page here -->http://www.diystompboxes.com/pedals/tubedummy.html

Some pages ago we found we can raise R1 and R2 values, they are the first plate res. (pin 1) and the first grid leak res. (pin 2)
So I ask, would it be useful, asking for more gain, to raise the second plate res. (pin 6) and the second grid leak res. (pin 7) too?

The first cathode (pin 3) goes to ground thru the 50k gain pot and the second cathode (pin 8 ) directly to ground. I assume that if I omit the gain pot, so pin 3 to ground, I'd have max gain?!

Also, the heaters need 150mA - but what about the plate?! I read that in a class A amp at 100V the plate mA is 11.8...
how much current should the plates receive, at 12V and more?! will 30mA be enough?! I want to try it at higher voltages, up to 60V - I guess the polarized cap should have higher V value (not the ordinary 16V, but 35V or more?!)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: DougH on January 20, 2009, 08:49:38 AM
Quote
the EF86 is well known for being clean

Maybe, but the EF86 has a good bit of gain, which is useful for driving a PI/output-stage. See the AC15, DC30, etc.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: SirElwood on January 20, 2009, 11:13:38 AM
Maybe, but the EF86 has a good bit of gain, which is useful for driving a PI/output-stage. See the AC15, DC30, etc.

True. One of my favourite amps was my "orange AD15" with EF86 preamp. Really nice OD-sound from PI. Shame I never completed that build. :-\
Title: Re: Some Q's about the Valvy
Post by: frequencycentral on January 20, 2009, 12:44:42 PM
So I ask, would it be useful, asking for more gain, to raise the second plate res. (pin 6) and the second grid leak res. (pin 7) too?

Yes, raising the second plate resistor to say 470K will give a bit more gain, and raising the second grid leak resistor to 1M will too.

The first cathode (pin 3) goes to ground thru the 50k gain pot and the second cathode (pin 8 ) directly to ground. I assume that if I omit the gain pot, so pin 3 to ground, I'd have max gain?!

That is correct.

Also, the heaters need 150mA - but what about the plate?! I read that in a class A amp at 100V the plate mA is 11.8...
how much current should the plates receive, at 12V and more?! will 30mA be enough?!

Have a look at my "Murder One" (http://www.diystompboxes.com/smfforum/index.php?topic=73222.0)  amp - I'm running the plates of one dual triode and one pentode from the 60 volt / 20ma output of the MAX1044.

I want to try it at higher voltages, up to 60V - I guess the polarized cap should have higher V value (not the ordinary 16V, but 35V or more?!)

Whatever voltage you run at you should use caps rated higher than that voltage, so for 60 volts you should be using caps rated at 63 volts, or 100 volts to be on the safe side.
Title: Some Q's about the Valvy
Post by: Renegadrian on January 20, 2009, 01:28:34 PM
OK Rick, after reading your precious post, I am sure that the link and schem I wanted to share could be useful for our tube projects...
check this out...
http://w1.859.telia.com/~u85920178/power/vconv_01.htm

you can have 30mA at 60V, with a circuit that's quite simple to assemble...I already begun, think I am gonna end it tomorrow...

Be sure I'll report it back!  :icon_wink:
Title: Re: Some Q's about the Valvy
Post by: frequencycentral on January 20, 2009, 01:35:45 PM
OK Rick, after reading your precious post, I am sure that the link and schem I wanted to share could be useful for our tube projects...
check this out...
http://w1.859.telia.com/~u85920178/power/vconv_01.htm

you can have 30mA at 60V, with a circuit that's quite simple to assemble...I already begun, think I am gonna end it tomorrow...

Be sure I'll report it back!  :icon_wink:

Precious moi?

That's a very interesting schematic you linked to - very similar to the MAX schemo I'm using in many ways.
Title: Some Q's about the Valvy
Post by: Renegadrian on January 20, 2009, 01:39:23 PM
Yes, my friend...I saw that the max1044 is a little more expensive than 4 trannies (3 bc547 and 1 bc557), so I'd jump on this one if my experiment goes well...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: esdiezy28 on January 27, 2009, 08:24:48 PM
My thanks to all, especially Rick for helping me debug my power supply probs for my stock Valvecaster. I took a cue from the "Murder One" schematic and I had some TC1044s (its an equivalent to a Max1044) around so while I had the whole thing disassembled I thought I'd drop it in and see if it would work. I only used one stage (2 diodes, 1 10uf cap to pin 2, and one to ground) of voltage boosting, and I went up from 12V to 21V. It definately made my pedal louder, and richer sounding. Maybe even less compressed, IMHO. Either way it sounded AWESOME! Just wanted to confirm that the voltage boost from a 1044 will work in pedal setting like the Valvecaster. Thank you!!!
Title: Marsha Valve build report
Post by: Renegadrian on January 28, 2009, 06:22:18 AM
I just built the Marsha Valve by Erik Hansen - altough he provided a vero layout too, I didn't like it and redrew it from scratch.
here it is...

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38568&g2_serialNumber=3)

I am not so keen on hybrid circuits, but I wanted to try anyway, who knows...Actually it doesn't give that magic sound that a pure circuit like the Valvy can give...Too many components for a sound that's not so special...Also a well filtered PS is mandatory.
I personally don't like it that much...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Mtaya on January 29, 2009, 03:04:36 AM
Hi all  :icon_smile:

First of all, thanks a lot for this precious thread & for your help. I'm a beginner in DIY and I've learn a lot by reading your messages.

So, here are few pictures of my "Valvecaster" :

* Circuit
(http://img149.imageshack.us/img149/2801/imgp0181mp7.jpg) (http://imageshack.us)
(http://img149.imageshack.us/img149/imgp0181mp7.jpg/1/w771.png) (http://g.imageshack.us/img149/imgp0181mp7.jpg/1/)

Nota : it's the first time that I draw & realized my own PCB because normally I order them in an electronic shop but it's very long & expensive   :icon_rolleyes:

* Face Cover :
(http://img301.imageshack.us/img301/9594/imgp0179jd2.jpg) (http://imageshack.us)
(http://img301.imageshack.us/img301/imgp0179jd2.jpg/1/w747.png) (http://g.imageshack.us/img301/imgp0179jd2.jpg/1/)

Nota :  I have to drill the enclosure


My "little" contribution to this projec :

PCB (size 75*25mm):
(http://img242.imageshack.us/img242/1163/pcbvalvecasterdim75x25mey5.gif) (http://imageshack.us)
(http://img242.imageshack.us/img242/pcbvalvecasterdim75x25mey5.gif/1/w602.png) (http://g.imageshack.us/img242/pcbvalvecasterdim75x25mey5.gif/1/)

Based on this layout :

(http://img242.imageshack.us/img242/2053/nouvelleimage1qn4.png) (http://imageshack.us)
(http://img242.imageshack.us/img242/nouvelleimage1qn4.png/1/w625.png) (http://g.imageshack.us/img242/nouvelleimage1qn4.png/1/)

who became :
(http://img132.imageshack.us/img132/6551/renderkn9.gif) (http://imageshack.us)
(http://img132.imageshack.us/img132/renderkn9.gif/1/w701.png) (http://g.imageshack.us/img132/renderkn9.gif/1/)

Nota : S1-> Input Caps switch / S2 -> Resistors Switch / S3 -> Capacitors Switch


Questions : What kind of switches have you used for thoses because I tink that I haven't used the good one (For S1 I took a DPDT and for S2&S3 I took DPDT) ?  :icon_redface:

Cheers,

Taya
Title: Valvecaster
Post by: Renegadrian on January 29, 2009, 04:49:05 AM
Taya, (http://www.smileys.it/images/smileys_it_2202.gif) and thx for your contribution to the thread - it's so much apreciated from a newcomer - and hell that graphic rules...Tell me more about those mods, are they so useful?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Mtaya on January 29, 2009, 05:07:03 AM
Hi Renegadrian & thank you for your Welcome (we are neighbour because I'm French)

So I've found that schem' on a pdf file found somewhere in those thread, & I've worked on it for having a PCB because I doensn't like to used "drilled sheet"

I've just finished the wiring yesterday evening, so I prefer finish the project before giving my opinion on it  :icon_wink:
Title: Valvecaster Power Supply....
Post by: Big Dan on February 01, 2009, 01:54:34 PM
Ok, I think I have gone through most of this stuff. One quick question...I want to build one of these and I can see I'm gonna need to run a power supply with it. Can you guys reccomend a cheap 9 or 12 volt regulated power supply (wall wart)? I run batteries on my pedals so I don't want to have to buy an expensive unit like a PP2. Surely somebody makes a nice cheap 12 volt source.

Thanks,
Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mth5044 on February 02, 2009, 04:55:55 PM
Check out the 1spot 12v powersupply. You can get it at MF and other similar sites and stores. If it's anything like their 9v, it will be very clean.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: castillogm on February 04, 2009, 02:24:11 PM
Finally I got my tubes from stewmac.com, I bought a pair of 12AT7, which I expect they sound neat. 

I also spend a hard time on finding 12AU7 locally but I finally got 4 from a small repair center (the last four tubes in the whole city!), so I think it would be a great project to build a 2-channel valvecaster with one of each tubes.

But first things first...I'm building the basic Valvecaster, but I have some sort of questions before I start the project this weekend:

1) I couldn't find/get a tube base, so I must solder the parts (or wires) directly to the tube pins... Is there a problem if I do this?  I've never treated with tubes, so I don't know if my soldering iron would damage it.  I have decent skills on soldering, but this is new to me.

2) I've read few pages back that changing the input cap to a lower value would decrease the bassy or boomy sound of the v'caster.  I'm pretending to use a cap selector with a rotary switch, but I'm concerned about how many caps and their values... any suggestions?

Thank you all! 
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 07, 2009, 09:53:14 PM
Hi guys!
I have been reading all the pages for the last week and must say you guys are great, lots of info.
I have made a bunch of different circuits and etched several boards, but never anything with tubes!
So much to learn and understand LOL.
Anyway I have most of the parts ready for a twin Valve-caster, just waiting for the Russian tubes to show up.
I'am going to install the new board right into my Amp.
It's a 1981 Univox U65G 50 watt solid state amp.
Hoping to use 30volts at the plate and 12v at the heaters.

Heres a link to an easy to understand site on how a tube works and biasing.
http://www.tubedepot.com/whisbipo.html

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 08, 2009, 06:53:21 AM
1) I couldn't find/get a tube base, so I must solder the parts (or wires) directly to the tube pins... Is there a problem if I do this?  I've never treated with tubes, so I don't know if my soldering iron would damage it.  I have decent skills on soldering, but this is new to me.

I wouldn't do that - you'll have a hard time mounting the tubes to the enclosure without sockets. And what if you need to change a tube? They shouldn't be too heat sensitive though. Better to get some sockets - try ebay.

2) I've read few pages back that changing the input cap to a lower value would decrease the bassy or boomy sound of the v'caster.  I'm pretending to use a cap selector with a rotary switch, but I'm concerned about how many caps and their values... any suggestions?

0.033 or 0.022 will be less bassy.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 08, 2009, 09:45:18 AM
What do you think about putting a cap across VR1? Apparently it will help to increase the gain.
It would go between pin 3 and the ground.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 08, 2009, 04:42:10 PM
OK I have the Twin Valvecaster board etched and ready to be drilled . It's been a couple of years since I made one, had to re figure out how to do it :icon_rolleyes:
The two tube sockets will not be mounted to the board.


(http://i107.photobucket.com/albums/m297/biggy-boy/twincasterboard.jpg)


Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: castillogm on February 09, 2009, 10:56:13 AM
1) I couldn't find/get a tube base, so I must solder the parts (or wires) directly to the tube pins... Is there a problem if I do this?  I've never treated with tubes, so I don't know if my soldering iron would damage it.  I have decent skills on soldering, but this is new to me.

I wouldn't do that - you'll have a hard time mounting the tubes to the enclosure without sockets. And what if you need to change a tube? They shouldn't be too heat sensitive though. Better to get some sockets - try ebay.

2) I've read few pages back that changing the input cap to a lower value would decrease the bassy or boomy sound of the v'caster.  I'm pretending to use a cap selector with a rotary switch, but I'm concerned about how many caps and their values... any suggestions?

0.033 or 0.022 will be less bassy.

Thanks, Freq!  I started the project this weekend, and I used some sort of connectors to attach'em to the tube while I find a socket. For my disgrace, I didn't get nothing but a terrible hum.  The tube was lit, but no sound came out...  I hope I come with better news next week.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 14, 2009, 03:52:02 PM
COOL   got my twin Valvecaster working

I got my first ever DIY tube preamp working, it sounds good!
I built it into my 50 watt solid state amp. The amp was way to clean, could not get any overdrive or distortion on it before adding the twin Valvecaster.
But now it's got tons of overdrive  :icon_mrgreen: :icon_mrgreen:

I didn't bother adding the out put volume control but I think I'll add it in.

Thanks guys for all the great info. I would not have been able to make the preamp without this thread!

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on February 14, 2009, 05:06:27 PM
I'm sure this has been covered but I couldn't find it. I want to build a valvecaster running off 9v using a subminni 6111 tube, of which I have 40, as opposed to a 12AU7, of which I have one, and it is being used. The pinouts are different, yes? what changes do I need to make?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 14, 2009, 05:16:18 PM
I'm sure this has been covered but I couldn't find it. I want to build a valvecaster running off 9v using a subminni 6111 tube, of which I have 40, as opposed to a 12AU7, of which I have one, and it is being used. The pinouts are different, yes? what changes do I need to make?

(http://i210.photobucket.com/albums/bb292/frequencycentral/SubCaster-2.gif)

But you can use a 9 ohm / 1 watt resistor to drop your 9 volts to 6.3 volts for the heater instead of using the LM317 arrangement. A 10 ohm / 1 watt resistor would give you 6 volts, which is still within the tubes spec.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 16, 2009, 04:50:00 PM
OK need some help with grounding.
I'd like to improve the grounding on my printed circuit boards.
I want to start using ground planes to help reduce noise.
To go one step further Id' like to have two ground planes. One audio signal GND plane and one power GND plane.

I've included a schematic (not mine)
Can someone point out which grounds in the schematic are audio signal GNDs and which ones are power GNDs?

(http://i107.photobucket.com/albums/m297/biggy-boy/TwinPeaksSchematic2-1.jpg)

Thanks
Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on February 16, 2009, 08:35:49 PM
  Read RG's star grounding article over at  http://www.geofex.com  it has all the info your looking for.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 16, 2009, 09:30:45 PM
  Read RG's star grounding article over at  http://www.geofex.com  it has all the info your looking for.

Hi Jered thanks for the link
Lots of great info on that site. I book marked it!
Yup well aware of the star ground principle.
I'm looking for different info thou.
I want to take it further and separate the signal grounds and the power grounds in a tube circuit. tubes are new to me and I'm trying to learn what portions of the circuit is power and what is signal. Ground planes are large areas of copper on a printed circuit board used as a common ground point the star. So I'm looking at basically having
two ground planes (stars) on the circuit board. One for power GNDs and one for signal GNDs. The two planes are then joined with a trace and then to the chassis.

I just need help figuring out what the GND points are in the diagram I posted.

My guess would be:
 signal GND  R1, R3, R6, R8, pot 4
 power GND pot 1, pot 2 and all the GNDs connected to the cathodes.


Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: schlendrian on February 17, 2009, 10:50:19 AM
hey everybody,
any news on a current working tubecaster project with a EF86?
I'm highly interested in soundsamples, bugs, issues, suggestions and so on with this one.
I'm planning to get myself a 48V DC power adapter to have higher anode voltage and get the 6.3V with the usual LM***
thoughts on that?

alternatively I thought about getting more voltage from a wall wart with this schematic:
(http://forum.musikding.de/vb/attachment.php?attachmentid=2332&d=1233246454)

help is mucho appreciated,
greetings from hamburg, germany
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on February 17, 2009, 11:17:39 AM
Hallo schlendrian from Renegadrian and (http://www.smileys.it/images/smileys_it_2202.gif)

I only know about this EF86 project, not a Valvy based one...
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=38344&g2_serialNumber=2)

The image you tried to post don't show - try to post it again
I used a voltage multipier, so I'd go with a common wall wart at 12V, a 7812 or 7806 for the heaters and the multiplier (the one I build gives out 50V)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: schlendrian on February 17, 2009, 12:26:29 PM

hey there! yeah I saw that schematic recently which got me pretty excited about this project.
since the EF86 would sound significantly better and would've had more distortion with more voltage I thought about a power plug with already
48V 0,5A directly to the plate and then generate the 6.3V for the heating, can I do that with a 7806 as described in the schematic you posted?
would be this one:
(http://i63.photobucket.com/albums/h151/eisen-uli/guitar/48Vnetzteil.jpg)

here is the alternative with a 6V wal wart transforming the voltage up to about 200V for the plate:
(http://i63.photobucket.com/albums/h151/eisen-uli/guitar/attachment-1.gif)

Pollin is a special shop over here, so don't worry about the numbers. :D
what do you think about it?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 17, 2009, 12:54:25 PM
Hi
You had mentioned about dropping the voltage from 48 volts to 6.3 using a regulator!
from 48v to 6.3v would be asking alot from one regulator.  It would need a big heat sink to dissipate the heat coming off of it, plus I think they have a voltage max of 40V.
I guess you could put a resistor in series with the regulator to create a voltage drop.  But it would have to be able to also handle the heat it would need to shed. 3 or 5 watts??

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 17, 2009, 01:06:36 PM

I guess you could put a resistor in series with the regulator to create a voltage drop.

Glen

213.5 ohm / 8.54 watt @ 200ma

To use a voltage drop resistor to drop 42.7 volts (48 - 6.3) it would have to be 213.5 ohm / 8.54 watt. That would be one huge resistor. Does such a resistor exist even?

42.7 / 0.2 = 213.5 (ohm)

42.7 x 0.2 = 8.54 (watt)

I think when dropping this much voltage you should be thinking transformer.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 17, 2009, 01:19:29 PM

I guess you could put a resistor in series with the regulator to create a voltage drop.

Glen

213.5 ohm / 8.54 watt @ 200ma

To use a voltage drop resistor to drop 42.7 volts (48 - 6.3) it would have to be 213.5 ohm / 8.54 watt. That would be one huge resistor. Does such a resistor exist even?

42.7 / 0.2 = 213.5 (ohm)

42.7 x 0.2 = 8.54 (watt)

I think when dropping this much voltage you should be thinking transformer.

If you put the resistor  in-front of a regulator you would  not have to drop the voltage down to 6.3v just drop it down to say 12 volts feeding the regulator.
You would still need a heat sink on the reg.  48 -12 = 36 / .2 =  180 ohm    36 x.2 = 7.2 watts     LOL  it would still be a big ass resisitor.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 17, 2009, 01:26:21 PM
That would be one huge resistor. Does such a resistor exist even?
LOL  it would still be a big ass resisitor.

Second item from the bottom, 220 OHM 10 WATT 10% CERAMIC BLOCK RESISTOR-SIZE: 1-7/8"L x 3/8"H x 3/8"D @ $2.50, http://www.electronicplus.com/content/ProductPage.asp?maincat=RE&subcat=REG
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on February 17, 2009, 01:39:00 PM
Something else to take into consideration.
Manufactures usually rate their power supply voltage output at there full amp rating. The voltage at no load and at half the specified max load would be higher.
This should be considered when selecting the size of the resistor. The open  no load voltage I would guess to be someware around say 52 volts or maybe a bit more??
With a 200 ma load and the load of the tube. the voltage would still be higher then the 48 volts.

Glen
Title: Soft sound.
Post by: firethorn on February 20, 2009, 11:26:49 AM
Help!

I've followed the schematic located in the first post or on beavis' page (the normal one, not the pcbless, etc) to the letter in my implementation of the valvecaster. Discovered a few issues like the gain pot being wired the wrong way round (yes, following the schematic visually, how lazy of me) and the same for the tone pot, both of which have been fixed.

The main problem is that I don't hear much difference in sound. In fact, with the pedal engaged at full volume and gain, the output volume is softer. It's so much softer that putting my gain pot slightly below full will result in no sound. From my understanding of the schematics, even if the volume pot happened to have been reversed, it would make no difference to the sound.

All resistors and solderpoints have been checked. I can't check the caps but I trust em. Except..... For axial electrolytic caps, the arrow points from +ve to -ve right? I always have doubts when it comes to caps.

I have slight hum when I put the wires connected to the tube socket so close together but other than that, it's fine.

I need help! It's unholy for a overdrive pedal to sound softer than it's bypass!
Title: Re: Soft sound.
Post by: frequencycentral on February 20, 2009, 12:50:09 PM
Help!

I've followed the schematic located in the first post or on beavis' page (the normal one, not the pcbless, etc) to the letter in my implementation of the valvecaster. Discovered a few issues like the gain pot being wired the wrong way round (yes, following the schematic visually, how lazy of me) and the same for the tone pot, both of which have been fixed.

The main problem is that I don't hear much difference in sound. In fact, with the pedal engaged at full volume and gain, the output volume is softer. It's so much softer that putting my gain pot slightly below full will result in no sound. From my understanding of the schematics, even if the volume pot happened to have been reversed, it would make no difference to the sound.

All resistors and solderpoints have been checked. I can't check the caps but I trust em. Except..... For axial electrolytic caps, the arrow points from +ve to -ve right? I always have doubts when it comes to caps.

I have slight hum when I put the wires connected to the tube socket so close together but other than that, it's fine.

I need help! It's unholy for a overdrive pedal to sound softer than it's bypass!

Please post voltage sfrom each pin of you tube!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on February 20, 2009, 09:46:31 PM
Measure from the pin to ground right? Sorry.. Relatively new to this but getting the hang of it.

Pin 1 to ground is 9.2V
Pin 5 to ground is 9.2V
Pin 6 to ground is 4.8V

The rest are at 0V? Supposed to measure from Vref to these pins?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 21, 2009, 07:24:23 AM
Measure from the pin to ground right? Sorry.. Relatively new to this but getting the hang of it.

Pin 1 to ground is 9.2V
Pin 5 to ground is 9.2V
Pin 6 to ground is 4.8V

The rest are at 0V? Supposed to measure from Vref to these pins?

It would be nice to see voltages at all 9 pins. Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

As you are running at 9 volts, all your voltages will be 25% less than mine. Your voltage at pin 1 is much too high, it should be 25% of the power supply voltage, so you do have a problem around that pin, perhaps the resistor value is wrong or you have a short? Also, what power supply are you using? Is it filtered/regulated? What voltage does it supply? What is its ma capability? The arrows on an electrolytic cap point to it's negative side.

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Big Dan on February 21, 2009, 08:54:28 AM
Here is a question for you folks. Will a 5964 tube work in this apllication? I know it is a 7 pin and I would have to change the pinouts, but would it work? I only ask becasue I have a few of them and I may try building it with it instead.

http://tdsl.duncanamps.com/show.php?des=5964 (http://tdsl.duncanamps.com/show.php?des=5964)

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 21, 2009, 09:03:07 AM
Here is a question for you folks. Will a 5964 tube work in this apllication? I know it is a 7 pin and I would have to change the pinouts, but would it work? I only ask becasue I have a few of them and I may try building it with it instead.

http://tdsl.duncanamps.com/show.php?des=5964 (http://tdsl.duncanamps.com/show.php?des=5964)

Dan

With that particular tube both the cathodes are connected, so you would have to tie pin 7 to ground, ditch the Valvecaster gain control and instead have an interstage gain control in place of the second stage grid resistor.

Also bear in mind that the heater is 6.3v / 450ma, so you will need to drop voltage for the heater with resistor ( 13 ohm / 3 watt @ 12 volts, or 6 ohm / 2 watt @ 9 volts should do the trick) or voltage regulator (7806 or LM317)

http://frank.pocnet.net/sheets/127/5/5964.pdf
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Big Dan on February 21, 2009, 10:03:54 AM
Wow, thanks for the informative reply. I guess I will stick with a 12AU7 for my first go around. Maybe after that I'll try something different.

Dan
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on February 21, 2009, 11:39:06 AM
Measure from the pin to ground right? Sorry.. Relatively new to this but getting the hang of it.

Pin 1 to ground is 9.2V
Pin 5 to ground is 9.2V
Pin 6 to ground is 4.8V

The rest are at 0V? Supposed to measure from Vref to these pins?

It would be nice to see voltages at all 9 pins. Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

As you are running at 9 volts, all your voltages will be 25% less than mine. Your voltage at pin 1 is much too high, it should be 25% of the power supply voltage, so you do have a problem around that pin, perhaps the resistor value is wrong or you have a short? Also, what power supply are you using? Is it filtered/regulated? What voltage does it supply? What is its ma capability? The arrows on an electrolytic cap point to it's negative side.



Actually I meant the rest are at 0V. The resistors are correct. Probably a short.. Weird though.

Am using a 1spot think it's v2. Puts out "9V". ~9.2-9.4 when measured without load. It's regulated and can put out 1.5A. SMPS but very well filtered.

With this information in hand(esp the sample values) I can now try to troubleshoot it myself. Will post back once I get something.

Thank you very much for your reply. Most people don't realise that even the simplest things can spark off a chain reaction for someone else in the direction of self discovery. =D. Again, thanks. =)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on February 23, 2009, 06:47:41 AM
Retested the resistors and noticed that R2 was coming up at 0R. Switched it out and it worked. Weird though that when I measured it before, it read correct. Not the "I could've sworn it was correct" situation, but the "I know what I saw" kind. Very odd.

Pedal is lovely. Can't seem to tell much difference when using a 12ax7 or the 12ay7 though. Will have to try it out on a bigger amp probably.

Thanks so much for the help frequency central. I've fixed my pedal and I've learnt about a half a dozen new things.

Cheers,
firethorn.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on February 23, 2009, 12:31:46 PM
Retested the resistors and noticed that R2 was coming up at 0R. Switched it out and it worked. Weird though that when I measured it before, it read correct. Not the "I could've sworn it was correct" situation, but the "I know what I saw" kind. Very odd.

Pedal is lovely. Can't seem to tell much difference when using a 12ax7 or the 12ay7 though. Will have to try it out on a bigger amp probably.

Thanks so much for the help frequency central. I've fixed my pedal and I've learnt about a half a dozen new things.

Cheers,
firethorn.

No problemo! Glad you got it debugged and working, and glad to have been some help. I found this awesome forum via this particluar thread less than a year ago, I have learned so much, so it's good to give some back.  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: syndromet on February 23, 2009, 01:21:20 PM
Man, this thing sounds great! Thanks a lot for such a wonderfull and easy project. Great project for "tube-starters".
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Mtaya on February 26, 2009, 06:08:48 AM
Hi everybody,

I'm still looking for modifying my Valvecaster & I would have a little technical question about this :

I know that "Heater power Voltage" is around 12V under 150mA but I would like to know how to mesure "plate voltage" ?

Thank's for your help

Taya

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: armstrom on February 27, 2009, 11:06:53 AM
plate voltage is just what it sounds like. If you measure the voltage between the plate of a triode (pin 6 or pin 1 on a 12AU7) to ground, that is your "plate voltage". Now, when most people talk about a particular plate voltage they're really talking about the plate voltage at idle (no signal applied to the input of the circuit). The plate voltage is primarily affected by the power supply voltage, the plate resistor, the cathode resistor and the transconductance curve of the triode. Another interesting voltage to check is the cathode voltage. This dictates the bias point of your tube (assuming you're using a self-biasing scheme).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Mtaya on February 27, 2009, 11:34:16 AM
Thanks a lot for your help  :icon_mrgreen:
Title: help me dubug it
Post by: dcd666 on February 27, 2009, 04:10:42 PM
hey everyone!
i'm a newbie and i'm having trouble with this simple box.
here are voltages:
pin1 - 8.91v
pin2 - 0.40v
pin3 - 0.00v
pin4 - 0.00v
pin5 - 9.12v
pin6 - 9.02v
pin7 - 0.27v
pin8 - 0.00v
pin9 - 4.36v
my wallwart is 9.12v
any ideas?
Title: Re: help me dubug it
Post by: frequencycentral on February 27, 2009, 09:55:38 PM
hey everyone!
i'm a newbie and i'm having trouble with this simple box.
here are voltages:
pin1 - 8.91v
pin2 - 0.40v
pin3 - 0.00v
pin4 - 0.00v
pin5 - 9.12v
pin6 - 9.02v
pin7 - 0.27v
pin8 - 0.00v
pin9 - 4.36v
my wallwart is 9.12v
any ideas?

Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

As you are running at 9 volts, all your voltages will be 25% less than mine. Your voltage at pin 1 is much too high, it should be 25% of the power supply voltage, so you do have a problem around that pin, perhaps the resistor value is wrong or you have a short? Your pin 6 voltage is also far too high, it should be about 70% of the supply voltage, check the value of the plate resistor at pin 6 and check for shorts.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on February 28, 2009, 06:38:01 AM
i've replaced both resistors: R2 & R3 and it's still the same.
voltages on pin1 and 6 are much too high.
i've followed by this schem:
http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=32777&g2_serialNumber=3
any ideas what i'm doing wrong?
i'll try to post some photos later.

edit:
here are photos:
(http://img253.imageshack.us/img253/9683/s5000020.th.jpg) (http://img253.imageshack.us/my.php?image=s5000020.jpg) (http://img89.imageshack.us/img89/3130/s5000022.th.jpg) (http://img89.imageshack.us/my.php?image=s5000022.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on February 28, 2009, 11:30:25 AM
Have ye triplequad checked that all the resistors are functioning with an ohmeter?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on February 28, 2009, 06:01:36 PM
yep.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 01, 2009, 07:27:56 PM
General Note after playing with a new 12AU7 pre-amp all day on the breadboard....

Increase grid leak resistors from 720K - 1M5 for a brighter clearer sound. Wont be as boomy and dark. Don't go too high, the affect will be minimal and those large value resistors are noisy. I think you can go as high as 22M though, that's if your plate current does not exceed 5mA.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on March 05, 2009, 06:13:29 AM
ok. now it works. it was just a matter of bad wallwart.
but i can't figure out how to put a DPDT with LED into it... (i don't need a true bypass).
can you help with it?
by the way - it's nice a sounding box :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on March 05, 2009, 06:42:39 AM
http://www.geofex.com/tektips.htm

Right at the btm, stomp switch wiring
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on March 05, 2009, 07:04:06 AM
bypass works just fine but still i can't add a LED indicator to it :icon_sad:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on March 05, 2009, 04:55:30 PM
Use a stereo input jack. The method where the effect can't be turned on unless there's a jack plugged in the input.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: mothercruncher on March 11, 2009, 06:04:40 PM
Just finished my Valvecaster build, stuck an Electro Harmonix LPB in front of it for a very effective kick that takes the pedal into nice heavy overdrive territory. Really pleased with the build, thanks Beavis and thanks Renegadrian for the vero layout. Here's my take on the whole "relic" thing applied to pedals;

(http://i395.photobucket.com/albums/pp31/mothercruncher/Guitar%20Pedal%20Builds/pic_top.jpg)

(http://i395.photobucket.com/albums/pp31/mothercruncher/Guitar%20Pedal%20Builds/pic_inside.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 11, 2009, 06:45:48 PM
Hey that's a great pedal! I am glad I have a part in it in some way... :icon_redface: :icon_surprised:
I like it!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 11, 2009, 07:14:23 PM
Whats the trimpot do Mr. Landgraff?  ;)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 11, 2009, 07:28:26 PM
Whats the trimpot do Mr. Landgraff?  ;)

Looks like it's the LPB's volume. Like the distressed look!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 11, 2009, 08:07:49 PM
Looks good man!


Has anyone been using shielded cable in the signal path?
I've been using RG174/u between the input jack and pin1, pin 7 and the output jack.
But I'm wondering if it's really needed? It's a pain in the a$$ to work with.
Any thoughts?

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 11, 2009, 08:32:02 PM
I wouldn't bother. Its not the kind of circuit that really would benefit much from coax cable.

Id regulate your heaters and give them stiff filtering and move on with it and play!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 11, 2009, 09:41:47 PM
Ok thanks
I'm almost done this build, its the second Valvecaster.
This one will be running at 140 volts.
I'm using the Real McTube transformer setup.


Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 02:19:39 PM
hey there
i've recently built a valvecaster, but i'm having a few problems, after building the circuit and testing it it didnt work, the valve lights up  and i hear a hum the volume knob seems to be working cus it cuts the hum, the tone knob when its all the way down also cuts the hum, and the gain seems its not working, i checked the connections to see if any where missplaced or soldered together, i know there is alot of possibilities of what could be wrong, but if anyone has an idea it would be apreciated
i'm new in electrinics and i know little about it i'v tried this has my first project so please take it easy on me :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 14, 2009, 03:19:42 PM
hey there
i've recently built a valvecaster, but i'm having a few problems, after building the circuit and testing it it didnt work, the valve lights up  and i hear a hum the volume knob seems to be working cus it cuts the hum, the tone knob when its all the way down also cuts the hum, and the gain seems its not working, i checked the connections to see if any where missplaced or soldered together, i know there is alot of possibilities of what could be wrong, but if anyone has an idea it would be apreciated
i'm new in electrinics and i know little about it i'v tried this has my first project so please take it easy on me :icon_wink:

Hi, good that the valve lights up! The hum would be a power supply issue - tubes are choosy. What power supply are you using? Is it filtered/regulated? What voltage does it supply? What is its ma capability? You may be able to solve the hum by using a 7812 (search this thread) and a 100uf cap across the power rails, or by using a good filtered/regulated power supply. The gain not working suggests maybe you wired the pot wrong? Does your guitar signal pass through the effect at all?

It would be nice to see voltages at all 9 pins. Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

If you are running at 9 volts, all your voltages will be 25% less than mine.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 03:52:18 PM
hey there
i've recently built a valvecaster, but i'm having a few problems, after building the circuit and testing it it didnt work, the valve lights up  and i hear a hum the volume knob seems to be working cus it cuts the hum, the tone knob when its all the way down also cuts the hum, and the gain seems its not working, i checked the connections to see if any where missplaced or soldered together, i know there is alot of possibilities of what could be wrong, but if anyone has an idea it would be apreciated
i'm new in electrinics and i know little about it i'v tried this has my first project so please take it easy on me :icon_wink:

Hi, good that the valve lights up! The hum would be a power supply issue - tubes are choosy. What power supply are you using? Is it filtered/regulated? What voltage does it supply? What is its ma capability? You may be able to solve the hum by using a 7812 (search this thread) and a 100uf cap across the power rails, or by using a good filtered/regulated power supply. The gain not working suggests maybe you wired the pot wrong? Does your guitar signal pass through the effect at all?

It would be nice to see voltages at all 9 pins. Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

If you are running at 9 volts, all your voltages will be 25% less than mine.
thanks for the relply
the values on the power supply is 9vdc 800ma, but i dont think thats the only problem (if its a problem), the bypass signal works but wen i turn it on i only ear the hum and no guitar signal, the gain potenciometer i have has an off switch forgot to mention that, i simply didnt connect anything to the other two pins it had (could that be the problem?)
i've tried to mesure the pins on the valve but i dont know how lol
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 14, 2009, 04:44:38 PM
thanks for the relply
the values on the power supply is 9vdc 800ma, but i dont think thats the only problem (if its a problem),

Is it regulated/filtered?

the gain potenciometer i have has an off switch forgot to mention that, i simply didnt connect anything to the other two pins it had (could that be the problem?)

If it's the type with a switch grafted on the back it souldn't be a problem. Did you have a look at the Valvecaster wiring diagram on Dano's site? Second diagram down: http://www.beavisaudio.com/projects/ValveCaster/

i've tried to mesure the pins on the valve but i dont know how lol

You have a multimeter? Set it to 'volts'. Clip the black lead to ground somewhere, and clip the red lead to each pin of the tube in turn. Note down your readings for each pin. If you don't have a mulitmeter you could use your tongue and estimate - but a multimeter is more accurate!  :icon_mrgreen: Might also be a good idea to check that you're giving the circuit the correct polarity from the power supply, if ground reads -9 volts you have it reversed.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 05:21:17 PM
Is it regulated/filtered?

my newbish prevents me from understanding how to see that lol sorry

If it's the type with a switch grafted on the back it souldn't be a problem. Did you have a look at the Valvecaster wiring diagram on Dano's site? Second diagram down: http://www.beavisaudio.com/projects/ValveCaster/

i did it's wired that exact same way only with a true bypass switch

You have a multimeter? Set it to 'volts'. Clip the black lead to ground somewhere, and clip the red lead to each pin of the tube in turn. Note down your readings for each pin. If you don't have a mulitmeter you could use your tongue and estimate - but a multimeter is more accurate!  :icon_mrgreen: Might also be a good idea to check that you're giving the circuit the correct polarity from the power supply, if ground reads -9 volts you have it reversed.

i have a multimeter only its analogic when i trie to mesure the first pin, the needle tries to go down so i cant read any of the pins, the few that move the needle makes it go down, could it be reversed has you said?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 05:31:11 PM
I just tried a 12v power supply I have laying around and the humming stoped!
but still no signal from the guitar to the amp
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 14, 2009, 05:52:54 PM
i have a multimeter only its analogic when i trie to mesure the first pin, the needle tries to go down so i cant read any of the pins, the few that move the needle makes it go down, could it be reversed has you said?

Yup, sounds reversed. Test the polarity of the power supply - the 'protocol' for effects pedals is centre=ground, most wall warts (yours too?) are the reverse of that.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 05:59:19 PM
the polarity symbol on the power suply is this (http://wombatula.com/electronics/polarity.png)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 14, 2009, 06:22:09 PM
Thats the opposite of effects pedal protocol. You can cut off the power supply lead and solder it on the other way around, using electrical tape to make good and isolate the wires from each other. The tube probably won't have suffered any damage - they're tough cookies.

Also bear in mind that if you have a metal chassis DC socket you will need to isolate it form your (metal) enclosure, or the positive will short against it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 14, 2009, 06:33:52 PM
i have a socket with a little holder in metal, i'm presuming that doesnt make contact with the tube circuit or am i wrong?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 14, 2009, 07:11:13 PM
i have a socket with a little holder in metal, i'm presuming that doesnt make contact with the tube circuit or am i wrong?

If the chassis is plastic and just the nut is metal then thats fine.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: waky on March 14, 2009, 10:41:36 PM
Guys i have been following this thread for a while and i really want to make my own valvecaster, but over here a tube is like 60$ a single tube T_T .... Is it really worth it? :P if so, i'll build one :icon_biggrin:!!!

PD: 1000 Posts on this thread  :o :o :o :o
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 14, 2009, 11:10:41 PM
Its a cool unit, I would never pay $60 for a new stock tube though. Well fro a generic 12AU7...

Why not order from another coutntry or a cheaper source?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: waky on March 14, 2009, 11:34:45 PM
its almost impossible to order anything from outside in venezuela :P.... the sources ive found are these ....


http://www.audiopormenos.com/tubos-de-vacio.html... it reads for a 6l6 "179 bs." the ratio to a dollar is 2,15... so 179/2,15 is 80$!! i realize its a power tube and probably preamp tubes are cheaper. But still is way too expensive =/ thats the only sourve ive found here :(



Edit: Just so you see how big of an overprice here...  a big muff for around  200$
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Jered on March 15, 2009, 04:51:02 AM
  Waky, send me your address in a PM
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 15, 2009, 05:27:34 AM
  Waky, send me your address in a PM

Jered, you're a saint...you know why... :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 15, 2009, 10:08:13 AM
Just found this on istructables, seems interesting...thought it should have its place in this topic...

The ValveLiTzer: Low-voltage Tube Booster (http://www.instructables.com/id/The_ValveLiTzer_Low_voltage_Tube_Booster/)

(http://www.instructables.com/files/deriv/FQH/EREV/FQ6EBKK7/FQHEREVFQ6EBKK7.MEDIUM.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 15, 2009, 04:12:42 PM
If the chassis is plastic and just the nut is metal then thats fine.

fixed! i used a new  power supply and it works!
thanks for your help
has soon has i put it in the case i'l post some pics
just one thing the overdrive kinda fries how can i make it less fried?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: waky on March 15, 2009, 06:48:22 PM
  Waky, send me your address in a PM
Pm sent!!, Are ya from venezuela too?


Renegadrian: Did you build that Valvelitzer?, How does it sound?.
Title: Valvy
Post by: Renegadrian on March 15, 2009, 07:19:02 PM
No, I didn't build it, just found it googling around...

----------------------------------------------------------------

I have to report my breadboard experiment with the Valvy...I used the voltage multiplier (http://w1.859.telia.com/~u85920178/power/vconv_01.htm) I built (I got up to 56V with an unregulated 12V wall wart)
Let me tell you that this simple circuit just breathes a new life with the added voltage...I'd reccomend everyone the voltage mult. I built, it's so easy and so useful with those tube project (as I started my own experiment, the TUBE STAR being my first creation!) - Also it's even cheaper than the 1044 circuit...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: waky on March 16, 2009, 12:05:24 AM
does that voltage doubler works well with tubes  supplying so little current? (probably a noob question but iv'e never built anything tubey  :icon_razz:)
Title: Voltage Multipliers (for our tube projects...)
Post by: Renegadrian on March 16, 2009, 02:52:06 AM
It provides enough current to make a tube work good...(actually it is a multiplier, not just a doubler...)
I built some tube stuff, and that VM gave me good results on every of them I tried it on...(Valvy, Tube Star, Pentaboost...)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Altec on March 17, 2009, 06:37:11 AM
OMG! Two nights, a lot of coke, a bunch of tree branching into other articles, schematics, random links, and material price searching later and I'm done reading through pretty much every post in this thread! Learned a bunch of stuff! I think I may have to give one of these a shot! I'm thinking the Pentabooster up front, the Twin-Caster setup, and maybe a diode clipping setup at the end with a toggle for a boost switch.

You guys think a booster after the 'Caster section would be needed for the clipping? I read in the thread somewhere about it being needed because of the clipping lowering the signal, but would the Penta, and Twins be enough to not need it (Just a little volume tweaking)?

Also, if anyone is interested, I have a text file with what I considered to be the good info from the thread. I can copy, and paste it if wanted. It's a bit long though lol.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 17, 2009, 01:27:03 PM
OMG! Two nights, a lot of coke, a bunch of tree branching into other articles, schematics, random links, and material price searching later and I'm done reading through pretty much every post in this thread! Learned a bunch of stuff! I think I may have to give one of these a shot! I'm thinking the Pentabooster up front, the Twin-Caster setup, and maybe a diode clipping setup at the end with a toggle for a boost switch.

You guys think a booster after the 'Caster section would be needed for the clipping? I read in the thread somewhere about it being needed because of the clipping lowering the signal, but would the Penta, and Twins be enough to not need it (Just a little volume tweaking)?

Also, if anyone is interested, I have a text file with what I considered to be the good info from the thread. I can copy, and paste it if wanted. It's a bit long though lol.

So how many litres of cola did you get through? I think diode clipping would be a bit of a shame, the Valvecaster has plenty of gain and crunch anyway, good tube clipping - so why add clipping diodes? Having said that, you could make it a switchable option for more tones. Try some Ge diodes, they will clip sooner and smoother, or have switchable Ge/Si. There should be enough volume/boost available for you not to need any booster after the diodes. Build a Pentaboost as a seperate pedal, then you can use it where you want - does sound good before the Valvecaster though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Altec on March 17, 2009, 01:58:30 PM
OMG! Two nights, a lot of coke, a bunch of tree branching into other articles, schematics, random links, and material price searching later and I'm done reading through pretty much every post in this thread! Learned a bunch of stuff! I think I may have to give one of these a shot! I'm thinking the Pentabooster up front, the Twin-Caster setup, and maybe a diode clipping setup at the end with a toggle for a boost switch.

You guys think a booster after the 'Caster section would be needed for the clipping? I read in the thread somewhere about it being needed because of the clipping lowering the signal, but would the Penta, and Twins be enough to not need it (Just a little volume tweaking)?

Also, if anyone is interested, I have a text file with what I considered to be the good info from the thread. I can copy, and paste it if wanted. It's a bit long though lol.

So how many litres of cola did you get through? I think diode clipping would be a bit of a shame, the Valvecaster has plenty of gain and crunch anyway, good tube clipping - so why add clipping diodes? Having said that, you could make it a switchable option for more tones. Try some Ge diodes, they will clip sooner and smoother, or have switchable Ge/Si. There should be enough volume/boost available for you not to need any booster after the diodes. Build a Pentaboost as a seperate pedal, then you can use it where you want - does sound good before the Valvecaster though.

First, let me say: Thank you Rick! Your contributions to this thread have been great, and I love your tube designs!

If I had to guess, I'd say 2 liters a night. Wasn't as bad as I thought now that I think about it! The diode clipping was more of a "Why not" for me. I'm forever playing with different settings on my amp, and my parametric EQ, so more options the better!  :icon_biggrin:

Thanks for the info man! Guess I gotta put together a shopping list!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: archaon13 on March 17, 2009, 05:01:50 PM
i'v heard that ceramic caps arent very good for sound is that true?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on March 18, 2009, 06:47:52 AM
I get hiss when I use them.. Supposed to take out the rf buzz but i get more.. bah...
Title: 6AU6 LONEWOLF
Post by: Renegadrian on March 19, 2009, 06:09:35 PM
Don't rememner if I already posted it...
Jon Anderson Lonewolf (http://jonanderson.mn.googlepages.com/tubebooster)

(http://jonanderson.mn.googlepages.com/schematic.jpg)

Anyway, as the sound clip was so interesting, I got this on my breadboard, and man, it's so good...I run it at more than 50V with my voltage multiplier and with some tweakings...
220 plate res.
47k instead of the 50k res
47k at the input
33µF at cathode cap
22nF instead of 10nF at the output

Also I like to put a pot to the cathode cap, I don't know if it can be conventionally done, but hey it just sets the gain!

----------------------------------------------------------------------------

EDIT - I have to report another success in the submini field - I found those 6205 I bought some months ago on the bay soooooooo good in the above schematic, just mind the different pinout...
I am going to experiment a little with those little pentodes...Let's see...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on March 20, 2009, 02:00:00 PM
here comes mine valvecaster:

(http://img18.imageshack.us/img18/7773/s5000002.jpg)

works really nice.

big thanks goes to Adriano for his help.
Title: YEAH
Post by: Renegadrian on March 20, 2009, 09:12:30 PM
WOW Pavel, I love the way it turned out - I am glad if I helped you somehow... :icon_redface:
Simple but nice to the eyes - I am sure it's good to the ears too, isn't it?!  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on March 21, 2009, 07:30:13 AM
don't be so humble Adriano :icon_wink:
oh yeah it's very good.
i've had some problems with power supply but i coped with it.
all the parts used were recovered from old radio, stompboxes, etc.
i haven't spent even a penny :icon_biggrin:
that's why it looks how it looks... :icon_smile:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 22, 2009, 07:19:49 AM
Thanks for the link Renegadrian!  The sound clips sound good! This is definitely one that I want to build also.

Just a quick question, is there a connections next the 68K resistor and the 150K variable resistor (where the red circles are)?

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/axe-boxes/6au6.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 22, 2009, 07:26:17 AM
Just a quick question, is there a connections next the 68K resistor and the 150K variable resistor (where the red circles are)?

I would say no there are not. Also consider making the 50K screen resistor a higher value, and having a cap to ground from the screen.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 22, 2009, 09:19:33 AM
Just a quick question, is there a connections next the 68K resistor and the 150K variable resistor (where the red circles are)?

I would say no there are not. Also consider making the 50K screen resistor a higher value, and having a cap to ground from the screen.

The Screen cap to ground where does it go? on the left side of the resistor ( between the screen and resistor ) or the right side of the resistor?

Also can I use a EL84?


Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 22, 2009, 09:51:17 AM
Just a quick question, is there a connections next the 68K resistor and the 150K variable resistor (where the red circles are)?

I would say no there are not. Also consider making the 50K screen resistor a higher value, and having a cap to ground from the screen.

The Screen cap to ground where does it go? on the left side of the resistor ( between the screen and resistor ) or the right side of the resistor?

Also can I use a EL84?


Glen

Left side, have a look at my Pentaboost, which is similar: http://www.diystompboxes.com/smfforum/index.php?topic=70524.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on March 22, 2009, 02:00:22 PM
Thanks Rick!   :D

Updated schemo:

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/axe-boxes/6au6-2.jpg)
Title: pentodes
Post by: Renegadrian on March 22, 2009, 08:34:01 PM
Yeah, that's it, the suppressor and the cathode go togheter - the input goes to the grid and the output has no connection with the screen.

Basically pentodes share the same schematic (I studied some in the last days, like mark lavelle's you can see at his site http://www.harmonicappliances.com/index.html (http://www.harmonicappliances.com/index.html)) and every schem I saw has that screen cap.
I tried to put one in, but it's not so mandatory, you can just try but it sounds good without, so I wouldn't bother...
You can have a 220k instead of that strange 150k (a 150k pot?!) and you can surely play around raising that screen res.
If you want more gain, put an electro cap at the cathode, say 33µF, maybe tied to a small value pot, 1k-10k.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 23, 2009, 09:20:05 AM
Just finished building this and I only get a clean boost when the effect is engaged ?? There's no overdrive sound whatsoever. I used this layout:

http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/Valvecaster-no-tone.jpg.html

I can hear a 'difference' if you know what I mean. The signal is definately passing through the tube.

Any ideas ??
Title: Valvy
Post by: Renegadrian on March 23, 2009, 11:03:49 AM
Don't know, man, that layout is verified by myself and other people too...Check the voltages and compare them to the ones posted by Rick a couple of pages ago...Also, check back every connection on every pin, and maybe the res. values, maybe you got one wrong?!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 23, 2009, 11:37:15 AM
I'm running this off 9v. Would that affect the effect ??
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 23, 2009, 12:37:33 PM
I'm running this off 9v. Would that affect the effect ??

Sorry 1878, I can't help you until you change your avatar! Why would anyone come from Liverpool and support 'the other team' as they are referred to in my house?

Seriously though, you should be getting some nice dirt at 9 volts, but as Adriano says, post your voltages, check your resistor values and solder connections.

Rick

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 23, 2009, 01:20:06 PM
Q: How many 'Liverpool' supporters does it take to change a lightbulb ??
A: 5... 4 to change the lightbulb and one to make sure they all get back to Bristol safely.

You should have more respect for your parent.

I'll check and post the voltages tomorrow. All componant values are correct, the valve heats up/glows but no overdrive. I bought a JJ Tesla ECC82 which I'm hoping will do the job. Volume control works as does the gain, it's just there's no gain to control :(
Title: Valvy
Post by: Renegadrian on March 23, 2009, 01:35:42 PM
Maybe you inverted the tube pins?!
http://www.dogstar.dantimax.dk/tubestuf/pinout.htm (http://www.dogstar.dantimax.dk/tubestuf/pinout.htm)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 24, 2009, 06:24:51 AM
Luckily for me, the pins are numbered on my socket. Made my first foray into tubes a bit easier !! Here's my voltages using a well filtered 9v power supply:

1: 7.03
2: -0.15
3: 0.01
4: 0.00
5: 9.20
6: 8.05
7: -0.15
8: 0.00
9: 4.61

Hmmm.....

Thanks again.
Title: Valvy
Post by: Renegadrian on March 24, 2009, 09:21:01 AM
Those are the voltages Rick posted of his Valvy some pages ago - As you can he runs it at 12V so some values are to be a little higher.

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

What it differs too much is the voltage you get at pin 1 - post the value of the res. wired to the plate.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 24, 2009, 09:56:25 AM
The resistor is 220k and the capacitor is 0.047uf (47nf) which are correct to the layout. Just checked all the other values and they're also correct. I've double checked the wiring/soldering also. Everything seems fine.

I'm getting a nice sparkly valve boost but no overdrive.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 24, 2009, 12:37:38 PM
Yup, your pin 1 should be 25% of the power supply voltage - about 2.3v in your case.
Your pin 6 should be 66% of the power supply voltage - about 6 volts in your case.

This seems to be a common debug problem with Valvecasters - the plates being too high.

Those voltage of mine that Adriano posted were taken with the gain set to maximum (ie first stage cathode grounded) by the way.

If you are sure everything is correct (though it can't be if your voltages are off), you could replace the 220K resistor with a 1M pot (use the pot's lugs 1 and 2) and tweak it until you read about 2.3v at pin one. Then measure the resistance between lugs 1 and 2 of the pot. Do the same with the 100K at pin 6, though I think pin 6 will come into line when you sort out pin 1.

Title: For those of you who want to try a 12AX7 in a Valvecaster
Post by: frequencycentral on March 24, 2009, 03:18:47 PM
For those of you who want to try (or have tried with poor results) a 12AX7 in your Valvecaster, I have some ideas.........

12AU7 is a medium mu dual triode
6111 (Subcaster) is also a medium mu dual triode

12AX7 is a high mu dual triode
6112 is also a high mu dual triode

I just breadboarded a Subcaster using a 6112 in place of a 6111 - blarty due to too much gain, so I experimented with a couple of resistor values and would recommend:

For a 12AX7 Valvecaster: change R2 to 100k, change R4 to 100k.

For a 6112 Subcaster: change R5 to 100k, change R6 to 100k.

I haven't got any 12AX7 to try this with, but I'm assuming that a 12AU7 is roughly equal to a 6111, and a 12AX7 is roughly equal to a 6112, based on mu.

I've got an idea for a new very dirty high gain tube pedal based on my little experiments with 6112 (should work well with 12AX7 too), it's working title is "Promiscuous Girlfriend" - watch out for the thread!
Title: Valvy
Post by: Renegadrian on March 24, 2009, 06:29:06 PM
ok Rick, I'll try that one tomorrow!  :icon_wink:
Altough my tries with the Tube Star went nowhere with the AX...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: panterica on March 25, 2009, 10:07:09 AM
here comes mine valvecaster:

(http://img18.imageshack.us/img18/7773/s5000002.jpg)

works really nice.

big thanks goes to Adriano for his help.

Hey dcd666. I like that enclosure you used. Where did you get it?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dcd666 on March 25, 2009, 11:02:59 AM
i'm glad that you like it.
enclosure was an old amp switch made by polish manufacturer KODA.
now it's called EXAR but i think they don't produce these enclosures anymore.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 26, 2009, 01:54:23 PM
Hey there guys :) I made a valvecaster and sadly... I don't think I made it correctly :D

All i get when I turn the volume/gain is a brrmmmmm. No sound from guitar, just brm...... The tube filaments light up and stuff, and gets hot. I think they may be running at a higher voltage .... anyways... any1 got a PCB layout and PnP version? I just can't debug with hanging layouts ;(
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 26, 2009, 03:37:00 PM
Hey there guys :) I made a valvecaster and sadly... I don't think I made it correctly :D

All i get when I turn the volume/gain is a brrmmmmm. No sound from guitar, just brm...... The tube filaments light up and stuff, and gets hot. I think they may be running at a higher voltage .... anyways... any1 got a PCB layout and PnP version? I just can't debug with hanging layouts ;(

Huh? PNP transistors? not tubes?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 26, 2009, 04:26:36 PM
press n peel stuff. toner transfer pcb. not transistors ofc :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 26, 2009, 05:39:23 PM
Ohhh i see!
I use a laser printer and print on ink jet glossy photo paper. Then use a hot cloths iron and heat it onto the board, then soak it in hot water to peel the paper away.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 26, 2009, 06:36:46 PM
no no no, you still got me wrong :D

I was wondering if any1 has a PCB for toner transfer + the PCB layout for this project. I tried building it normally, with the provided layout and I failed. Now, I can't debug it cuz I am only used to debugging pcb projects. Also it's too chaotic this way :S
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: firethorn on March 27, 2009, 09:56:38 AM
no no no, you still got me wrong :D

I was wondering if any1 has a PCB for toner transfer + the PCB layout for this project. I tried building it normally, with the provided layout and I failed. Now, I can't debug it cuz I am only used to debugging pcb projects. Also it's too chaotic this way :S

define failed.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 27, 2009, 11:46:01 AM
didn't have a 220k resistor, so I wired a few old russian resistors (from around 1970s)... anyways, all I get is brmmmm. The guitar signal doesn't go out the amp and well the tube gets ultra mega hot, I burned myself on it ;(

That is why I am asking for a pcb version, so I can make it properly :D
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 27, 2009, 01:06:40 PM
didn't have a 220k resistor, so I wired a few old russian resistors (from around 1970s)... anyways, all I get is brmmmm. The guitar signal doesn't go out the amp and well the tube gets ultra mega hot, I burned myself on it ;(

That is why I am asking for a pcb version, so I can make it properly :D

Well here's my little contribution to this awesome thread.   :D
Here's a smaller PC board for this cool little pre.  I've used it and verified that it works.  Haven't hooked up the voltage divider section but it should work too. 

The trace and components are exactly mirrored so, fold on the line and  iron the trace and components on the PC at the same time.
This is 300dpi image.

(http://i215.photobucket.com/albums/cc70/tr-stompboxes/MatsumiTubeVertPinsTrace.jpg)
(http://i215.photobucket.com/albums/cc70/tr-stompboxes/MatsumiTubeVertPinsTraceDetail.jpg)

(http://chawk.files.wordpress.com/2008/04/trurl_pagecontent2.jpg)
(http://chawk.files.wordpress.com/2008/04/trurl_pagecontent-12.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 27, 2009, 03:17:02 PM
gee thanks man :) I saw those, guess I'll make them

Oh and I just realized my mistake... I wired everything while looking on the wrong side of the socket....
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on March 27, 2009, 03:43:52 PM
gee thanks man :) I saw those, guess I'll make them

Oh and I just realized my mistake... I wired everything while looking on the wrong side of the socket....

That'll get ya every time. :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tednet on March 27, 2009, 04:08:02 PM
bleh I am getting even more confused >.< Do those numbers show the pins of the tube, or the pins of the socket >.<
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 27, 2009, 05:33:51 PM
1 is pin 1 of the tube, the pcb posted is like having the tube glass point pointing at you.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 27, 2009, 07:06:06 PM
Here is a vero layout I did for the subcaster, can anyone verify it? Schematic found here.
http://www.diystompboxes.com/smfforum/index.php?topic=66746.0

(http://i301.photobucket.com/albums/nn71/svsguitarhero/DIY%20My%20layouts/Subcaster10.gif?t=1238195003)
I'm using a resistor instead of the LM317 setup, and the tube is oriented like this:

1         8
2         7
3         6
4         5

Thanks!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 27, 2009, 07:35:11 PM
I'll check it tomorrow, too tired now...Well, my eyes are, my ears not, so I am playing with the TRIODE TRIODE and with JERED 6021 HIGH GAIN - I like them both, built them some time ago and forgot them...Give them a try!!!

The second is more on the bass side, but has more gain, while the first is a good medium gain overdrive...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 27, 2009, 08:09:14 PM
Here is a vero layout I did for the subcaster, can anyone verify it? Schematic found here.
(http://i301.photobucket.com/albums/nn71/svsguitarhero/DIY%20My%20layouts/Subcaster10.gif?t=1238195003)

The 14 ohm should be 18 ohm / 2 watt. The 470K can just be 1/4 watt. You have also missed the 100K plate resistor at pin 8.

I did this perf layout for another forum member some while ago, you could take just the part you need and ignore the LM317 bit. It's not verified, but I think it's correct. The layout is designed to mount inside an enclosure like how I did my Pentadriver and Vintage Vibe, if you know what I mean.

(http://i210.photobucket.com/albums/bb292/frequencycentral/Subcaster2.gif)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 27, 2009, 08:21:43 PM
Wow, don't know how I missed the resistor.
I think the resistor should be 14 or 15 ohms though, since I'm running this at 9v, that gives me 6.4v and 6v, respectively.
I meant for the three watt resistor to be R1. Why do you say it only needs to be two? What is the current of this?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 27, 2009, 08:28:44 PM

I think the resistor should be 14 or 15 ohms though, since I'm running this at 9v, that gives me 6.4v and 6v, respectively.
Why do you say it only needs to be two? What is the current of this?


OK, for 9 volts then:

6111 heater: 6.3v / 300ma
Voltage drop required: 2.7v

2.7 / 0.3 = 9 (ohms)
2.7 x 0.3 = 0.81 (watts)

So a 10 ohm / 1 watt resistor will give you 6 volts @ 300ma. Thats an easy value to find and within the tolerance of the heater.  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 27, 2009, 08:45:32 PM
Ah, I was doing my math wrong! I had to find for the needed drop. That makes way more sense. Thank you much.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 27, 2009, 09:01:52 PM
How about this
(http://i301.photobucket.com/albums/nn71/svsguitarhero/DIY%20My%20layouts/Subcaster11.gif?t=1238202065)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Kaffeetrinker on March 28, 2009, 08:34:41 AM
Hi! Regarding the Valvecaster...I m thinking about breadboarding it and use the Beginner-Project-Boost circuit in front to make the tube really drive (or any other boost circuit if I might find one I like more ;) ) as soon as I get a 12AU7. What woul you say? Does it make sense? Will afford a couple of changes/additions of course, but thanks to the breadboard^^
Title: Valvy
Post by: Renegadrian on March 28, 2009, 09:53:00 AM
Altough I like to go TUBE all the way, I did find a Tillman a good addition to the Valvy - It stays quite clear and doesn't add too much gain. So it boosts the tube in a "natural" way.
Rick finds a LPB a good addition, I tried but didn't like it, as Valvy is on the bass side and LPB too...
Try some booster and see what suits best for your ears. I'd suggest you Tillman - DOD 210 (labelled wrong in the gallery 201) - EA booster (first stage of the tremolo)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Kaffeetrinker on March 28, 2009, 11:08:36 AM
Yeah alright...maybe gotta fatten the signal a bit for my like...
but:
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album14/album143/DOD_201_JFET_PREAMP_VERO_001.gif.html?g2_imageViewsIndex=1 what does the red square with the red dot mean? its a cut connection line I guess?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 28, 2009, 11:12:41 AM
Yes, a break in the line
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 11:37:38 AM
Can anyone take a look at my layout? I tried building it last night without success and I want to make sure I'm working off a correct layout.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 28, 2009, 12:14:08 PM
Can anyone take a look at my layout? I tried building it last night without success and I want to make sure I'm working off a correct layout.

Your revised layout looks ok. But check that your breaks in the strips are actually 100% breaks - electrons only need a tiny connection too small for you to see with the naked eye. It's a common problem with stripboard, one reason I don't like the stuff. Use a continuity tester to determine this.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 12:48:01 PM
I do, and I also use a jeweler's loupe to check.

I found my mistake, I messed up on parts positioning. Thats what happens when you build at 1:30a.m. I guess.

Glad to know the layout looks good, I'll report back if I can get this working.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 01:37:26 PM
Well I fixed it (C3 was going from 10a to 10b instead of from 10a to 10c) but now I am running into quite an interesting problem. The 10 ohm resistor does nothing. I'm getting the full 9.16v on pin 3, and that probably killed my tube as well. I've tested the resistor, 10.2 ohms, I replaced the resistor and it still does the same thing.

What is going on?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on March 28, 2009, 02:02:49 PM
Sounds like it isn't drawing the current you think it is.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 02:21:00 PM
Bu its the exact same voltage as my power supply, so I doubt it. It seems like I have a short somewhere, but I measured with my DMM, and there is 10r between the 9.16v and pin three, which also reads 9.16v.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 28, 2009, 02:27:38 PM
Bu its the exact same voltage as my power supply, so I doubt it. It seems like I have a short somewhere, but I measured with my DMM, and there is 10r between the 9.16v and pin three, which also reads 9.16v.

Mystifying. I'm sure my calculation for the voltage drop resistor is correct. It could be a short. Have you any other way to derive the heater voltage? Like a LM317? I wonder if it would be possible to use a number of 1n4148 in series to drop the voltage........each one has a voltage drop of 0.7v if I recall. So four in series would drop 2.8 volts. Never tried it..........I wonder if it would work?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 02:31:43 PM
Hmmm, I like the 1n4148 idea. Do you think I destroyed my tube by running it with 9v on pin 3?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 28, 2009, 02:36:40 PM
Do you think I destroyed my tube by running it with 9v on pin 3?

Probably not. They are tough little @#$%ers. You may have reduced it's life a little though. I once accidentally ran 12 volts through a 6111 heater without destroying it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 02:38:18 PM
Wow, good to know. I'm going to go try that diode thing, I'll let you know if it works.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: snap on March 28, 2009, 02:47:13 PM
btw: where`s Stephane slajeune (http://www.diystompboxes.com/smfforum/index.php?action=profile;u=766;sa=showPosts) these days?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 28, 2009, 02:51:47 PM
Hey Rick, can you link to the datsheet for the 6111 and 5672? I can't seem to find them.

Edit: Nevermind, I found them.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Altec on March 28, 2009, 05:10:28 PM
Got a  5672, and two 12AU7's on order.  :icon_biggrin: If I like it enough, I may build a power amp, and build myself a practice amp!  :icon_biggrin:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: KorovaMilkBar on March 28, 2009, 05:35:55 PM
i just ordered the parts yesterday and hopefully i will get what i need, although i think i might have gotten a couple things wrong, i guess we will find out. it sucks since i cant find a decent components store anywhere in San Diego. anyone have any suggestions?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 28, 2009, 06:01:16 PM
i just ordered the parts yesterday and hopefully i will get what i need, although i think i might have gotten a couple things wrong, i guess we will find out. it sucks since i cant find a decent components store anywhere in San Diego. anyone have any suggestions?

EBay is a good source for parts, I get stuff all the time from Canadian dealers.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: KorovaMilkBar on March 28, 2009, 11:15:55 PM
thanks for the advice, fortunately i went to Fry's electronics today and they had just about everything i need. i just need the mono audio jacks and some sort of ac jack. i did get a universal ac adapter that has a connector that resembles a 9v battery so i might just throw in a battery jack instead. the radioshack by my house should have some mono jacks in by tuesday so i just need to grab that and the battery jack and the tube i ordered should be in by then. so ya! hopefully i will have all the parts and get started by next weekend. once im done and if it turns out good i will definitely post pictures!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 30, 2009, 08:03:11 PM
Alright, I got my layout working.
(http://i301.photobucket.com/albums/nn71/svsguitarhero/DIY%20My%20layouts/Subcaster11.gif?t=1238202065)
A couple problems with it, however.

1: Heater voltage is 5.96v, datasheet says 6.0v to 6.6v. Am I close enough? All I had were 10.7 Ohm 7 watt resistors.
2: Gain control does nothing.
3: I have less gain and slightly less treble with this than I do with my 12AU7 Valvecaster (no tone control version).

Any help would be appreciated.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on March 30, 2009, 08:10:15 PM
1: Heater voltage is 5.96v, datasheet says 6.0v to 6.6v. Am I close enough? All I had were 10.7 Ohm 7 watt resistors.

That's close enough I think! What's 0.04v between friends? The Subcaster was designed to run at 12 volts, so you're on new ground running it at 9 volts. I suspect you might have to experiment with the plate resistors, maybe sub them for pots and see if you can dial in the appropriate value? You should also be aware that 6111 will show very different voltages to 12AU7 using in the same circuit.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 30, 2009, 08:14:19 PM
I was expecting I'd have to tweak a few things running it at 9v, (I had to for the pentaboost) but the fact that the gain pot has NO affect makes me think it might be more than that.

Oh well, I need more practice with a breadboard anyways.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 30, 2009, 08:39:16 PM
Check your gain pot it might be faulty.

Clearly the pot has some resistance as if it didnt the tube would not work as it would not have a bias reference point. It could be shorted and going right to ground, this would provide a mu-follower and the circuit would work. Is there a lot of gain though, if so the cathode is going straight to ground.

It's hard to tell whats going on from your vero layout. The tubes are unclear.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on March 30, 2009, 09:32:05 PM
Tube is the same way Rick does his, like this
(http://i210.photobucket.com/albums/bb292/frequencycentral/Subcaster2.gif)



I'm using a resistor instead of the LM317 setup, and the tube is oriented like this:

1         8
2         7
3         6
4         5

Thanks!

One other thing. Why not use a 6.2v Zener diode? You can buy ones rated at 500mA for peanuts. This curcuit only draws 300mA, right? wouldn't work for all the submini stuff, but a cheap, easy and safe alternative for others. No clue why I just now thought of it.
http://cgi.ebay.com/50-pcs-Zener-Diodes-500mW-6-2V-5-Axial-Motorola-HQ_W0QQitemZ300304216297QQcmdZViewItemQQptZLH_DefaultDomain_210?hash=item300304216297&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A15|39%3A1|240%3A1318
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 1878 on March 31, 2009, 05:05:15 PM
I haven't been able to get my Valvecaster build to work properly. It's got plenty of clean boost, but no overdrive. I'm putting an order in for parts tonight, so I'll get a couple of new pots etc and re-build the thing from scratch.

Also, I'm thinking of putting in a voltage doubler to boost it to 18v. Would there be any probs in this ??
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 703224796 on March 31, 2009, 05:10:25 PM
Hey guys........I've been eyeing this project for months now, and just recently I got my hands on a 120v > 9v transformer.  if I flip it, I can crank out 120v from a 120v>9v wallwart. Now I know that the 12--7 tubes like these values a lot more, so I was wondering if any of you know where I can find a project like that, OR how can I Mod this guy to make it run off of 120v.  


ohh yeah, I would heat the heaters from the 9v coming from the wallwart.......smart or not?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on March 31, 2009, 06:05:51 PM
I know very little about trafos, anyway I read somewhere you should be able to turn the trafo the other way around and get a good voltage - I believe it should be something less of the specified value, but no less than 100V in your case.
I also feel that you should somehow turn that AC into DC (is it mandatory, is it a better or it just doesn't matter?)
Also, sure you have a 9V (AC?) for the heaters (while 12V would be surely best)

I don't think there are mods to be applied at the main schem - I run mine at 50V - just apply the V at the plates...(pins 1 and 6)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on March 31, 2009, 06:13:11 PM
The only problem I see is that you might not have enough juice in your wallwart (but then again you might).  Your heaters will need a few hundred ma and then you have to remember that if you need 10 ma for your plates (not likely) with a 10:1 winding ratio, you will need at least 100 ma from your wallwart.  I would recommend a fairly high powered zener for the regulation from 9V down to 6.3V.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on March 31, 2009, 06:15:20 PM
Tubes must run on DC.

The 9V AC when rectified will be 12.7V so that is fine for series wiring of the heaters. Add some filtering and regulation and your set!

Your transformer setup will work fine as long as you put 9V AC onto the 9V side of the transformer.

The plate resistors and cathode resistors will need to be altered with the increased voltage. Cant say where to, I would experiment on the bread board first.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: 703224796 on March 31, 2009, 06:55:41 PM
you guys are great! thanks a ton for the prompt responses.......I'm guessing that SSrectifier would be used, so that the heater can be used in the 12v config.  also, I believe I would leave the tone and volume sections the same, while the plate resistors would need to be changed to something calculated from ohm's rule, right?  How about the Gain pot, does that stay?  I would also add something like an ssrectifier at the 120v section going to the plates and maybe a few large caps to filter............does it all sound correct?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on March 31, 2009, 08:08:33 PM
Hey guys........I've been eyeing this project for months now, and just recently I got my hands on a 120v > 9v transformer.  if I flip it, I can crank out 120v from a 120v>9v wallwart. Now I know that the 12--7 tubes like these values a lot more, so I was wondering if any of you know where I can find a project like that, OR how can I Mod this guy to make it run off of 120v.  


ohh yeah, I would heat the heaters from the 9v coming from the wallwart.......smart or not?
I'm running mine well with 157 volts and just a couple of resistor size tweaks
Two transformers back to back   in 120 volt/ 12 volt---- 12volt/120volt out rectified it's boosted to 157 volts

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: KorovaMilkBar on April 01, 2009, 11:41:07 PM
hello! i just got a package from mouser and i messed up on the potentiometers. they are 1 b50k and 2 b100k (the plans call for a100k). they are also the receding (sp) thumbdial kind. so are these any good or should i head to radioshack? thanks!

mike.

p.s. i should be getting the tube anyday now, soon as i do i will be working away on this! im so excited!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on April 04, 2009, 12:27:34 PM
Sorry to drag this up agian, but can I use a 6.2v Zener diode for the heater? Wouldn't work for all the submini stuff, but a cheap, easy and safe alternative for some.
http://cgi.ebay.com/50-pcs-Zener-Diodes-500mW-6-2V-5-Axial-Motorola-HQ_W0QQitemZ300304216297QQcmdZViewItemQQptZLH_DefaultDomain_210?hash=item300304216297&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A15|39%3A1|240%3A1318
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 04, 2009, 12:38:27 PM
Sorry to drag this up agian, but can I use a 6.2v Zener diode for the heater? Wouldn't work for all the submini stuff, but a cheap, easy and safe alternative for some.
http://cgi.ebay.com/50-pcs-Zener-Diodes-500mW-6-2V-5-Axial-Motorola-HQ_W0QQitemZ300304216297QQcmdZViewItemQQptZLH_DefaultDomain_210?hash=item300304216297&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A15|39%3A1|240%3A1318

Are you still planning to un your Sub @ 9 volts? If so, you only need to drop 2.4 volts. That zener would drop 6.2 volts - ie. too much. Did you try 4x 1n4148 yet?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on April 04, 2009, 12:40:56 PM
I did, they melted. I thought a zener ALLOWS 6.2v to pass? The Crowther Audio Hotcakes has an 8.7v zener right off the DC jack if I remember correctly.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 04, 2009, 12:53:05 PM
I did, they melted.

Heheehe - my favourite experiments are the ones involving melting/fuming components! At least now we know.  :icon_biggrin:

I thought a zener ALLOWS 6.2v to pass? The Crowther Audio Hotcakes has an 8.7v zener right off the DC jack if I remember correctly.

Dunno, never used zeners.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 04, 2009, 02:31:03 PM
Zeners can be implemented to either drop their voltage or supply their rated voltage.  In series, a zener will drop its rated voltage.  If you stick it with the anode to ground, you will get their rated voltage at the cathode (this is how reference voltages are created, typically).  that is why I love zeners.  Also, you can get beefy 5W ones or bigger so that would handle subminis no problem, though you may have to glue them with thermal epoxy to the case or chassis for heatsinking.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on April 04, 2009, 04:44:25 PM
Why would I need 5w? If I'm doing the math right, I only need  around .9 watts. 1 watt should be fine, right?

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 04, 2009, 06:21:17 PM
1 watt will work, you might want a heatsink.  I only mentioned 5W because if you try to run multiple tubes, you need big ratings.  It was just a number.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on April 04, 2009, 07:18:31 PM
Why would I need 5w? If I'm doing the math right, I only need  around .9 watts. 1 watt should be fine, right?


A good rule of thumb whenever designing tube electronics of anything with HV or heat...double you power ratings. If a plate resistor could be 1/4W double it up to 1/2W. 0.9W is too close to 1W for me...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: KorovaMilkBar on April 06, 2009, 04:40:33 AM
hello! i just got a package from mouser and i messed up on the potentiometers. they are 1 b50k and 2 b100k (the plans call for a100k). they are also the receding (sp) thumbdial kind. so are these any good or should i head to radioshack? thanks!

mike.

p.s. i should be getting the tube anyday now, soon as i do i will be working away on this! im so excited!
anyone????
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 06, 2009, 09:31:46 AM
The taper will be off, which means the adjustment will seem a bit choppy and hard to find the sweet spot.  You can still use them, but if you can afford it, I would suggest getting the right ones because that will just make life easier.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: svstee on April 06, 2009, 12:21:59 PM
OK, I was comparing my 6111 to my 12au7 vavlecaster and noticed that the 6111 has quite a bit more bass. the 12au7 had plenty, so I'm a little concerned. Any way to get a hair less bass out of it? Also the 6111 doesn't break up as early unless you have a guitar with very hot pickups or some kind of boost in front of it. I assume this a result of running a 12v circuit at 9v, but what would I change to improve this (beside running it at 12v)?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 06, 2009, 12:28:01 PM
With tubes there is no real substitute for more voltage.  In terms of bass, you can change the input and output caps.  I built a tube booster with a .01 input and .047 output and that seemed to regulate the bass.  Also look at any cathode bypass caps, lower values will reduce the bass.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on April 06, 2009, 02:44:09 PM
I believe lowering the value of the cap between the two stages will also roll of some bass too.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 06, 2009, 03:41:49 PM
That is true, I guess I just lumped that with either the output or input cap because it is the output of one stage and input of the other.  You can also do some parallel resistor/capacitor things to tailor the frequency response between stages as well.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 06, 2009, 04:14:02 PM
Found THIS (http://music-electronics-forum.com/showthread.php?t=12281) googling...

Title: compressors?!
Post by: Renegadrian on April 06, 2009, 04:41:44 PM
http://www.dogstar.dantimax.dk/tubestuf/graphics/dz_tone.gif

http://www.triodeel.com/comp1.jpg
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 06, 2009, 04:48:29 PM
Found THIS (http://music-electronics-forum.com/showthread.php?t=12281) googling...



JKowalski is a member here too, surprised he hasn't mentioned it on this thread too. Innovative use of a charge pump to up the plate voltage!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: CynicalMan on April 06, 2009, 05:36:44 PM
This circuit looks too good to be true! I'd like to try it out with this tube:
http://tdsl.duncanamps.com/show.php?des=6J6A
I will be running off of proper heater voltage. What I'd like to know is, since the plates of the two triodes are connected, can I connect the cathode of the second tube to the gain pot instead of ground?
Also, are there any parameters in the datasheet I missed that would prevent it being used for audio or for low voltage?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 06, 2009, 06:21:47 PM
This circuit looks too good to be true! I'd like to try it out with this tube:
http://tdsl.duncanamps.com/show.php?des=6J6A
I will be running off of proper heater voltage. What I'd like to know is, since the plates of the two triodes are connected, can I connect the cathode of the second tube to the gain pot instead of ground?
Also, are there any parameters in the datasheet I missed that would prevent it being used for audio or for low voltage?

The plates are not internally connected, but the cathodes are. You could tie the cathodes to ground and use an interstage gain control though.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: CynicalMan on April 06, 2009, 09:18:59 PM

The plates are not internally connected, but the cathodes are. You could tie the cathodes to ground and use an interstage gain control though.

Right, cathode. I'm not good with tubes yet.  :icon_smile:

And the datasheet looks OK?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 07, 2009, 05:25:33 AM

The plates are not internally connected, but the cathodes are. You could tie the cathodes to ground and use an interstage gain control though.

Right, cathode. I'm not good with tubes yet.  :icon_smile:

And the datasheet looks OK?

Well its a medium mu twin triode, as is the 12au7, so worth a try. Jus't remember you can't use the regular Valvecaster gain control, it needs to be and interstage gain control.

http://www.pmillett.com/tubedata/HB-3/Receiving_Tubes_Part_2/6J6-A.PDF
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 11, 2009, 08:49:45 PM
I wonder if it would be possible to use a number of 1n4148 in series to drop the voltage........each one has a voltage drop of 0.7v if I recall. So four in series would drop 2.8 volts. Never tried it..........I wonder if it would work?

I've just been reading the 'Heaters' page over at Valve Wizard. Merlin says: " A pair of ordinary high-current silicon diodes can be added to the heater chain to drop the heater voltage by about 0.7V. (If using a DC heater supply, only one diode will be needed.)"

So I guess he means 1n400*, using four in series would drop 2.8v, using eight (seems a little excessive) would drop 5.4v.

There's also some really good info about series/parallel heaters and pairing mismatched heaters.

http://www.freewebs.com/valvewizard/heater.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on April 11, 2009, 08:57:08 PM
The Valve Wizard is great!
I've learned a lot from him, over the past month or so.
He was even kind enough to answer a couple of questions I asked him via Email.

glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: glenn.b on April 19, 2009, 04:19:42 AM
This is my first post here, on this site. I guess it is fitting that my first post be a request for help.  I have just finished building this based on Dano's schematic and layout all the way back at the beginning of this thread.  All I can manage to do is get a loud hum when I plug this into my amp.  I have noticed that if I put my hands on the input/ output jacks and press down just slightly, I can hear a very static filled, quiet sounding strum of my guitar strings.  I was hoping maybe that one of you that has been here would have an idea...Any good ideas / thoughts/ suggestions would be much appreciated.  Thank you
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 19, 2009, 04:49:11 AM
Welcome aboard!  :icon_wink:

Does the tube light up?! Have you checked the pins? Maybe you read them au contraire?! How is the thing powered? Tube is 12AU7?! Tell us more - pics appreciated too.
Let's make another Valvy work!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 19, 2009, 07:17:35 AM
This is my first post here, on this site. I guess it is fitting that my first post be a request for help.  I have just finished building this based on Dano's schematic and layout all the way back at the beginning of this thread.  All I can manage to do is get a loud hum when I plug this into my amp.  I have noticed that if I put my hands on the input/ output jacks and press down just slightly, I can hear a very static filled, quiet sounding strum of my guitar strings.  I was hoping maybe that one of you that has been here would have an idea...Any good ideas / thoughts/ suggestions would be much appreciated.  Thank you

Posting your voltages at all 9 pins is an essential part of debugging. Here's mine, running at 12 volts, with the gain control set to maximum:

Pin 1: 3.02v
Pin 2: -0.518v
Pin 3: 0.00v
Pin 4: 0.00v
Pin 5: 11.97v
Pin 6: 8.21v
Pin 7: -1.285v
Pin 8: 0.00v
Pin 9: 5.91v

If you are running at 9 volts, all your voltages will be 25% less than mine.

Also worth reading this: http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lunchie on April 20, 2009, 01:34:02 PM
Today I found this article on makezine ... I thought that somebody could be interested ...

http://www.electricwestern.com/diytubes.html

Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: glenn.b on April 21, 2009, 04:10:57 PM
Thank both of you for the welcome!

Ok, this is pretty awful, but the values coming off my pins are way higher than yours, and I am only using a 9volt.  As far as pics I have tried to capture it, but normally the pic overexposes , due to me trying to shoot it to close.   My pins(sigh) are 1:9.24                                                                         
                                                                                                                                                      2:8.51                     
                                                                                                                                                      3:000
                                                                                                                                                      4:9.33
                                                                                                                                                       5:9.34
                                                                                                                                                      6:9.34
                                                                                                                                                      7:8.93
                                                                                                                                                      8:000
                                                                                                                                                      9:9.33

      Almost like there is a complete open.  Anyway there it is-geez, I know I'm new to this!






                                                                                             







Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: glenn.b on April 21, 2009, 04:12:27 PM
And yes, tube is a 12au7.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 21, 2009, 06:02:10 PM
1:9.24                                                                         
2:8.51                     
3:000
4:9.33
5:9.34
6:9.34
7:8.93
8:000
9:9.33

Check out your voltages and connections at pins 4, 5 and 9 first, that's the heater. Pin 9 should be half your supply, so about 4.5v. Pin 4 should be 0v and pin 5 should be 9v. Once you get the heater voltages sorted out we can look at the rest of you voltages, which will change once the heater is correct, so repost them. There should of course be no connection to pin 9, as it's the heater's centre tap and is unused in this circuit. Good luck, it will work eventually!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: glenn.b on April 23, 2009, 05:23:01 AM
Thank you again for the push and the encouragement!  When I get up tomorrow I will unsolder the whole works and then restart, working towards those numbers you gave me.  I will let you know what I come up with just as soon as I get it together.  gotta get the gremlin out...


Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: adynata on April 23, 2009, 05:46:15 AM
i have a fender champ 600, a newer one, that i hack on. it sounds really nice with this tube-booster in front of it. thanks, guys, for making these things tangible.

goodluck debugging glen.b
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 23, 2009, 10:49:21 AM
Welcome to both of you -  :icon_wink:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on April 27, 2009, 10:13:40 AM
Man this thread keeps going and going...

Has anyone come up with simple mods to the valvecaster to make it function as a simple buffer. Maybe with just a little gain?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 27, 2009, 11:46:34 AM
Man this thread keeps going and going...

Has anyone come up with simple mods to the valvecaster to make it function as a simple buffer. Maybe with just a little gain?

Yes it does Dano - it's been quite an inspiration. Though I think it's now offically too long to read!

Using just a single triode stage, a 100K plate resistor and a 100K cathode resistor, taking the output directly from the cathode through a cap value of your choice, will give you a non-inverting unity gain buffer.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: dano12 on April 27, 2009, 05:30:00 PM
Man this thread keeps going and going...

Has anyone come up with simple mods to the valvecaster to make it function as a simple buffer. Maybe with just a little gain?

Yes it does Dano - it's been quite an inspiration. Though I think it's now offically too long to read!

Using just a single triode stage, a 100K plate resistor and a 100K cathode resistor, taking the output directly from the cathode through a cap value of your choice, will give you a non-inverting unity gain buffer.

thanks buddy, I'll give that a try.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 27, 2009, 07:36:32 PM
If I recall, setting it up like that will actually give you slightly less than unity gain, but like .99 or something, just a technicality, but I remember reading somewhere that that is why some people prefer to not use a cathodyne phase inverter.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 29, 2009, 11:30:56 AM
Hello everyone!
I read almost all the replies in this thread and I built my valvecaster and then the twincaster; it's nice, but not really my favourite kind of sound.
Anyway, I still didn't get one thing: I tried to use an AD/DC transformer to power the circuit, and I get a quite loud constant hum, still I can hear the output of the pedal.
Why's that? Maybe a crappy transformer? If I use a 9V battery everything's fine, but I'd like to try to feed it with 12V.
The transformer has a trim that lets me choose the output voltage, and I tried 9V and 12V: the quite strange thing is that if I measure its output, I measure ~12.5V instead of 9V, and ~17V instead of 12V (if I recall correctly... I'm @ work right now :)). Can someone kindly shed some light on this? :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 29, 2009, 12:45:41 PM
Hello everyone!
I read almost all the replies in this thread and I built my valvecaster and then the twincaster; it's nice, but not really my favourite kind of sound.
Anyway, I still didn't get one thing: I tried to use an AD/DC transformer to power the circuit, and I get a quite loud constant hum, still I can hear the output of the pedal.
Why's that? Maybe a crappy transformer? If I use a 9V battery everything's fine, but I'd like to try to feed it with 12V.
The transformer has a trim that lets me choose the output voltage, and I tried 9V and 12V: the quite strange thing is that if I measure its output, I measure ~12.5V instead of 9V, and ~17V instead of 12V (if I recall correctly... I'm @ work right now :)). Can someone kindly shed some light on this? :)


Sounds like your power supply is an unregulated one. What you need to do is get a 7812 voltage regulator and use that to regulate down the ~17v to a stable 12v. Also, add a 100uf electro cap across the power rails from +ve to ground. That wil get rid of your hum issues and give you a nice stable 12v. This method is mentioned elsewhere in this thread, a lot of people have used it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 29, 2009, 01:32:47 PM
The reason why you measured higher voltage on your transformer is 1) it is unregulated and 2) they design wallwarts to deliver a MINIMUM of 9V at the rated current, so if you are drawing less current, then the voltage will be higher.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on April 29, 2009, 02:11:56 PM
Yes transformers can be real noisy sometimes.
My ValveCaster is housed in the same enclosure as a VooDoo lab OD, the valvecaster is powered by a transformer and is relatively quite.
The vooDoo is powered by a 9 volt battery.
 The two circuits are totally separate from one and other, two channels in, two channels out of the enclsure.
Yet if I use the Voodoo while the valvecaster is powered up I get all kind of noise bleeding into the surrounding wires of the voodoo circuit.

I think I need to isolate the voodoo wires going to the pots away from the 120 volt wires that feed the transformer for the valvecaster!!
For now I just use one or the other.


(http://i107.photobucket.com/albums/m297/biggy-boy/amp2.jpg)
left side ValveCaser in, right side Voodoo in. The outputs are on the back.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on April 29, 2009, 04:09:27 PM
I went to the reharsal yesterday, First time with this band, playing QUEENSRYCHE songs - me on the bass - I took my Valvy with me...Man, it's so good on bass...It just rounds up the sound to achieve the Eddie Jackson (bass god for me...) sound...
Just wanted to share this experience...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on April 29, 2009, 04:17:05 PM
  it's so good on bass...It just rounds up the sound to achieve the Eddie Jackson (bass god for me...) sound...
Just wanted to share this experience...

+1 about running a bass through it, sounds so good with a double musicman pickup.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 07:11:38 AM
frequencycentral, Ripthorn, thanks for the advices!
I bought today my 7812 and a small dissipator, and if I unterstood correctly what I have to do is:
- wire the transformer's output to the 7812's input
- take the output of the 7812 and feed the + pin of the electrolytic cap, while the - pin goes to ground
- take the +12V from the + pin of the cap
Right? :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 30, 2009, 11:12:47 AM
That is exactly right.  Don't forget to ground the regulator, it uses that for a reference.  Probably what I would do, though, is put an electrolytic cap before and another after the regulator, since the smoother the input voltage, the smoother the output voltage will be.  An extra few cents is worth it.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: terminalgs on April 30, 2009, 03:30:18 PM

If using 12.6v heater supply:  pin 9 is not used,  pin 4 and pin 5  are used.  give one 12v+ and ground the other. @12v the heater draw is 150ma.
If using 6.3v heater supply:  pin 4 and 5 are jumpered together and get 6v+ and pin 9 is grounded.  @ 6v the heater draw is 300ma.

9v is not enough for a 12.6v heater.  the current draw from the heater would kill a battery quick, so you ought to be using a transformer of some sort.  might as well be 12v instead of 9v.  better yet,  get a 120-200v transformer and give a 12ax7 high plate voltage.  everything becomes easy once you do this.


without a load, a power supply's voltage may be higher than the required 12..,  like 15-17,,  once you put the load across it ,, (the filament) it should drop to 12v (or just below).  are you getting a 17v reading with the filament as a load? or without the tube installed, across pins 4 & 5?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 04:12:21 PM
Guys, I tried the 7812 ant it outputs a nice 11.40V supply, but now, instead of a constant hum I get a constant buzz! :D
Terminalgs, I don't get it... do I have to modify the tube's wiring?  ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 04:55:05 PM
Update: I rebuilt the valvecaster and the buzz disappeared, but... It has a crappy sound! :( No sustain and a farty distortion... ???
Ok, I'll try to debug it--- just a question: is it normal for the tube to be quite hot (sorry for the n00bish question)?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 30, 2009, 05:38:30 PM
The tube will be hot to the touch, but it shouldn't be melting anything, etc.  If it has a fartish sound, that sounds like a biasing problem.  What current is your transformer rated at?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 30, 2009, 05:41:18 PM
Update: I rebuilt the valvecaster and the buzz disappeared, but... It has a crappy sound! :( No sustain and a farty distortion... ???
Ok, I'll try to debug it--- just a question: is it normal for the tube to be quite hot (sorry for the n00bish question)?

Post your voltages!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 05:57:00 PM
Sorry man, you're right! :)
Here are the voltages I measure at the tube's pins:
pin 1: 3.64
pin 2: 0.18
pin 3: 0.09
pin 4: 0.09
pin 5: 11.57
pin 6: 5.05
pin 7: -0.14
pin 8: 0.09
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 30, 2009, 06:02:25 PM
Sorry man, you're right! :)
Here are the voltages I measure at the tube's pins:
pin 1: 3.64
pin 2: 0.18
pin 3: 0.09
pin 4: 0.09
pin 5: 11.57
pin 6: 5.05
pin 7: -0.14
pin 8: 0.09

They look pretty good, apart from pin 6, which is 3v less than it should be. Check the resistor value, and for shorts/bridges.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 06:16:49 PM

They look pretty good, apart from pin 6, which is 3v less than it should be. Check the resistor value, and for shorts/bridges.
Ok, I'm a total n00b... I switched R3 with R4! :(
Now everything's ok! I thank you a lot, frequencycentral!! :)
Tomorroy I'll try to rebuild the twincaster, and I'll post some news about it!
Thanks again man! :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on April 30, 2009, 06:18:43 PM

They look pretty good, apart from pin 6, which is 3v less than it should be. Check the resistor value, and for shorts/bridges.
Ok, I'm a total n00b... I switched R3 with R4! :(
Now everything's ok! I thank you a lot, frequencycentral!! :)
Tomorroy I'll try to rebuild the twincaster, and I'll post some news about it!
Thanks again man! :)

Cool - up and running - that was a simple fix! Well done!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: lazerphea on April 30, 2009, 06:20:07 PM
Cool - up and running - that was a simple fix! Well done!
Thanks thanks thanks! :)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on April 30, 2009, 06:32:45 PM
No Mine only gets slightly warm to the touch.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on April 30, 2009, 08:26:59 PM
I should confess that i have never actually built the valvecaster, but I am doing some other tube projects.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kristoffereide on May 01, 2009, 04:35:30 AM
I just finished mine last night, and it sounds great!!! Full warm tone. A little hiss way way in the back, but I'll get to that. (any ideas what it could be?) I built mine in a BB, so I have the option for a twin. I like the look of a glowing tube, so I put a orange LED in the middle whole in the socket (i just jammed a 3mm in there). Looks amateurish, since I lost my socket screwes, but it works! I also keep the voltage to the tube on constantly, I just bypass the signal. Don't know it this is a good idea, but I guess off-ing and on-ing the DC to the tube isn't best for the tube...

(http://i651.photobucket.com/albums/uu237/kristoffereide/DSC00780.jpg)
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on May 01, 2009, 09:01:01 AM
Looks good!
I like the glow.
Ya It ok to leave the heaters going while it is in standby or bypassed, that way it is ready to go when you stomp on the switch.


Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kurtlives on May 01, 2009, 09:27:35 AM
Nice build

Almost all pedals are setup so the circuit is always drawing current, no matter if your signsal is going trhough or not.

If you cut the voltage everytime you hit the switch you'd have heater issues. You'd have to hit the switch and wait while the heaters "ramp up" and start emitting electronics before you got sound.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: kristoffereide on May 01, 2009, 09:58:15 AM
yes, you are right. When I think about it, all pedals only bypass the signal...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: tranceracer on May 01, 2009, 01:33:35 PM
Looks amateurish, since I lost my socket screwes, but it works! I also keep the voltage to the tube on constantly, I just bypass the signal. Don't know it this is a good idea, but I guess off-ing and on-ing the DC to the tube isn't best for the tube...

The black screws look good to me, matches the black knobs! 

Yes, as Kurtlives said keep the tube powered and just bypass the signal.  The tube changes tonal characteristics (at least mine does) as it warms up.  I personally like my Valvy's tone when it's still cold, has a more gritty tone.  After it warms up (20 minutes) the tone becomes a smoother overdrive.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 01, 2009, 02:18:01 PM
I should confess that i have never actually built the valvecaster,

Isn't there some law against that around these parts?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on May 01, 2009, 02:37:28 PM
I'm waiting for my account to be deactivated as we speak... I have a few 12au7's, but no sockets and my submini project is taking a lot of free time (but almost done).
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 01, 2009, 02:53:00 PM
I'm waiting for my account to be deactivated as we speak... I have a few 12au7's, but no sockets and my submini project is taking a lot of free time (but almost done).

I've reported your confession to the moderator. Pleading 'no sockets' is no defence. This kind of behavior really shouldn't be condoned or tolerated.


























.........and what the hell is a 'submini tube' ???
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on May 01, 2009, 04:15:07 PM
All this talk about submini tubes, could give a guy a inferiority size complex.
No honest, it's normally bigger like a ValveCaster.......
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 01, 2009, 05:31:20 PM
Quote from Mrs Biggy Boy: 'Oooh Glen - yours is the BIGGEST Valvecaster I've ever seen!'
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on May 01, 2009, 05:52:29 PM
Quote from Mrs Biggy Boy: 'Oooh Glen - yours is the BIGGEST Valvecaster I've ever seen!'

LOL
Ya but she was only saying that, to distract me while she took money out of my walet to go shopping. :-\
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 02, 2009, 05:45:48 PM
LOL - you guys make me laugh!  :icon_lol:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: panterica on May 04, 2009, 07:12:52 PM
Is there any news on the infamous Promiscuous Girlfriend yet?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 07, 2009, 09:42:13 AM
Hello! This is my first time posting here.

This thing sounds fantastic on guitar! My question is whether anyone has tried it on bass? Anyone have some sound clips of it on bass? I'm wanting to build an overdrive but I really don't like the jagged sounding nature of transistors for overdrive. You guys say that the stock Valvecaster is somewhat bassy sounding but would it need some larger value caps to let a bit more bass through anyway? I'm also guessing the tone stack would need a different cap to bring the response range down a bit.

Sorry for so many questions. I'm fairly new at pedal making and I've NEVER worked with tubes before.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Ripthorn on May 07, 2009, 09:59:49 AM
Look on the previous page, Adriano and someone else were talking about how good this sounds with a bass.  You could try it stock first and see if you like it.  If not, you can change in/out caps and tonestack values to get what you want.  You can use Duncan's tone stack calculator to make sure you get the right tone stack range.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: biggy boy on May 07, 2009, 10:05:21 AM
  My question is whether anyone has tried it on bass? 

Hi bassmanate welcome to the forum.
Yes it does sound good when used with a bass.
Especially if it is a lefthanded bass :icon_lol:
I have no sound clips to offer at this time though.
I roll back the gain to clean up the sound.

Glen
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Salvatore on May 07, 2009, 10:30:21 AM
I just finished mine last night, and it sounds great!!! Full warm tone. A little hiss way way in the back, but I'll get to that. (any ideas what it could be?) I built mine in a BB, so I have the option for a twin. I like the look of a glowing tube, so I put a orange LED in the middle whole in the socket (i just jammed a 3mm in there). Looks amateurish, since I lost my socket screwes, but it works! I also keep the voltage to the tube on constantly, I just bypass the signal. Don't know it this is a good idea, but I guess off-ing and on-ing the DC to the tube isn't best for the tube...

(http://i651.photobucket.com/albums/uu237/kristoffereide/DSC00780.jpg)

Nice going, I only think putting that tube beside the stomp switch is creepy.
In the heat of playing, and suddenly wanting to stomp valvy, I would certainly kick that tube out of commission fast.
Personally I would have put the tube above the pots to give the footswitch a little more space.
In this case you might consider putting around the tube some sort of cage, which also would provide extra protection when carrying it around..
(Ore you just want it lying on the same spot all the time, always engaged, in that case,, never mind.  :icon_wink: )
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 07, 2009, 10:38:06 AM
It surely helps to be lefthanded!  :icon_razz:
Well, I play both guitar and bass and I really enjoy my Valvy. I use the toneless version, and use the amp EQ for small adjustments, but it works just fine for my ears, I just plug and play! As the other southpaw wrote, you can get nice "fat" tone with the gain rolled down a little, to get a full but undistorted sound.
I got a good sound to play in a queensryche cover band (second reharsal for now...)

Wanna know the way it works with bass?! I uploaded a couple of samples I did some time ago.
hope that helps.

http://www.aronnelson.com/gallery/main.php/v/Renegadrian/bass-a.mp3.html
http://www.aronnelson.com/gallery/main.php/v/Renegadrian/bass-b.mp3.html
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 07, 2009, 03:18:27 PM
Very nice. Sounds like it will be capable of producing more than enough overdrive for me. Of course, I have a little dilemma now. My next project WAS slated to be an Orange Squeezer but after hearing this, I'm not sure which I want to do first. I really NEED a compressor for my rig but I really WANT a Valvecaster. Decisions, decisions...   :icon_mrgreen:
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 07, 2009, 04:35:28 PM
I built both - I definitely say GO VALVY!!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 07, 2009, 04:46:20 PM
Does the Valvy really provide that much compression to the signal? I don't have much experience with tubes (heck, all the bass amps I've ever owned have been good ole' reliable Hartke combos!) so I don't have much insight into how they alter the sound.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 07, 2009, 04:53:04 PM
I think I can say it acts like a compressor in its way...The sound on the bass is actually tight and round, very full...It boosts the signal in the best way! And I love to keep it as a booster with the gain at mid run or just add some grit turning it up...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 07, 2009, 05:00:35 PM
Ok, I think you just about have me convinced.

Hmmm...I saw MUCH earlier in the thread someone mention using a 12au7 in place of the 4558 in the Orange Squeezer...Perhaps this could be reversed and a switchable feedback compressor could be integrated into the Valvy...I'll have to think about this for a bit...
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 08, 2009, 10:41:58 AM
Alright, I think I've decided that I'm going to build the Valvecaster. I just have a few questions for you guys.

First, what brand tubes are you guys using? I don't want to go bottom of the barrel but I don't really want to spend more than $10-$15 on a tube.

Second, what all do I need to mount the tube? Obviously I need a socket. Will any 8 pin tube socket do? Looks like there's quite a selection at tubedepot.com. Is there anything else I need to secure the tube like a base or retainer since the tube will be sticking quite proudly out of the enclosure? Like I said before, I've never even owned anything with tubes in it much less built anything with tubes.
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: frequencycentral on May 08, 2009, 11:04:24 AM
Will any 8 pin tube socket do?

9 pin!!
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: bassmannate on May 08, 2009, 11:11:44 AM
Doh. That's right. I'm confusing myself because we're only USING 8 pins on the tube. So, any of the 9 pin sockets will work?
Title: Re: Tube boost + overdrive running off a 9 volt battery
Post by: Renegadrian on May 08, 2009, 11:18:20 AM
Alright, I think I've decided that I'm going to build the Valvecaster. I