Tube boost + overdrive running off a 9 volt battery

[Death Super Mario]

I soldered directly to the socket.
http://imageshack.us/photo/my-images/18/valvecaster.jpg/

You could use heat shrink, you can get large diameter at a Auto Repair place.  I have some that will go around a 8 pin Octal, so it would easily cover everything..   

while 12AU7 and 12AX7 do not get hot, others do, Well my 12AU7 got really hot, but I learned after wards that my LM7812 went bad and I was putting 30 volts on the heater

I have seen that some hot air blower similar to the soldering iron are used for shrinking heat shrink tightly onto. Can i use hairdryer ?

[zambo]

you can use a lighter if you want. it just reacts to heat, doesnt matter what kind. I use a lighter all the time. I dont know if a hair dryer gets hot enough. never tried it.

[iccaros]

I use a heat gun, made for removing paint. I have used hair dryers. Lighter.... I burn things so I stopped.. ) ..my dogs morning breath... what ever, just heat

[zambo]

lol...morning breath, I got to go breath on some and see if it works...

[Pigyboy]

Hey,
I have custom tube protectors for this project
http://www.diystompboxes.com/smfforum/index.php?topic=91656.0

[Bill Mountain]

I just finished this thread and I am really only left with one question before I begin.

If I build my pedal with a 78XX regulator in it, will I not be able to use a regulated power supply with it?  Like, if I let a friend borrow it and he puts it in his pedal board he won't be able to use his regulated power supply.  He'll have to use my wall wart.  Correct?  This is because there will be some voltage drop from the second regulator.  Am I thinking right?

This was discussed briefly in passing earlier in the thread and I never saw it mentioned again.

Thanks!

[iccaros]

@Bill

That depends, what is the regulated voltage from his supply. All pedals list a voltage on them, and all have a min requirement. It would be the same with using a resistor.. I am assuming that you are talking heaters..

So say you have 18 volts and you want to drop to 12, so 18 - 12  = 6. A 12au7 pulls .150 ma so 6/.150 = 40 ohms..  6*.150 = .9 watts (right math people ) so you would need a 1 watt min resistor (2 for safety)
but if you plugged this into a 12 volt supply this would no longer work as you would only get ~ 6 volts to the tube.

So The issues is not the regulator, but Ohms Law.. So if you plan on changing power you need to plan for this..

If your source will not exceed 35 volts a LM78XX is the best choice, as you can go from 14.5 - 35 volts with no real issues..  but if you do not have  min of 14 volts you may have issues.

This is true of every pedal on the market. Most are designed to go on a  peddle board in the first place, so they use voltage pumps or something like that if they need higher voltage than say 12v... my regulated supply goes to 48v, but that is for phantom power..

[CheopisIV]

Okay, I built this beast on a breadboard using Renegadrian's 'No Tone' vero and it works great and sounds great, but it does some weird things to my power supply!  

I have a 9V 300ma Boss adapter, a 12V 400ma random (noisy as hell) adapter and an 18V 6.5A Laptop adapter that I've tried.  I run it into a Beavis style I/O box with the V-Sag knob...

When I have the adapters on full (V-Sag maxed) all the voltages are slightly lower than usual, and any tweaking of the knob makes the Voltage jump all over the place (I have a Voltmeter inline), no smoothness to it.  It's a real pain trying to use the 18V and dial it down to 12.6V...pretty well impossible.  The 12V adapter usually runs at ~12.6V for other circuits, but with the Valvecaster it feeds 11.6V max, and the 9V feeds 9.x but drops to 8.7V with the Valvecaster circuitry.

I tried a couple filter circuits, one being the Beavis Huminator, but the Valvecaster refuses to work with the filtered 12V from that circuit...will only work with the raw power fed into it.

Is this a normal thing for the Valvecaster to create so much havok on the power side?  I may order some more parts to build a charge pump/regulator into the pedal, but I'd prefer to keep the cost to a minimum.  Anybody have this happen to them?  Does this even make sense??  

[iccaros]

Okay, I built this beast on a breadboard using Renegadrian's 'No Tone' vero and it works great and sounds great, but it does some weird things to my power supply!  

I have a 9V 300ma Boss adapter, a 12V 400ma random (noisy as hell) adapter and an 18V 6.5A Laptop adapter that I've tried.  I run it into a Beavis style I/O box with the V-Sag knob...

When I have the adapters on full (V-Sag maxed) all the voltages are slightly lower than usual, and any tweaking of the knob makes the Voltage jump all over the place (I have a Voltmeter inline), no smoothness to it.  It's a real pain trying to use the 18V and dial it down to 12.6V...pretty well impossible.  The 12V adapter usually runs at ~12.6V for other circuits, but with the Valvecaster it feeds 11.6V max, and the 9V feeds 9.x but drops to 8.7V with the Valvecaster circuitry.

I tried a couple filter circuits, one being the Beavis Huminator, but the Valvecaster refuses to work with the filtered 12V from that circuit...will only work with the raw power fed into it.

Is this a normal thing for the Valvecaster to create so much havok on the power side?  I may order some more parts to build a charge pump/regulator into the pedal, but I'd prefer to keep the cost to a minimum.  Anybody have this happen to them?  Does this even make sense??  

Voltmeter in line? you are measuring from ground to something right.. you only have voltage if you have resistance.. so I am not sure what in line is.. That is how you measure current..

so what are your voltages on the pins?


The heaters draw 150ma and the rest well 1 ma I believe (12/100K  is around .1 ma right.. so if your wall warts can not really put out the 500ma, then it will drop voltage on load (other things draw current also so you have to take that in to account)

you only need the heaters @ 12 or really 12.6 but 12 is good..
so drop 6 volts at .150 ma..
a 2 watt resistor on your heaters @ (6 /.15  = ) 40ohms at  ( .15*6 = ) .9 watts of dissipation.. so 1 watt is good, 2 better.

[CheopisIV]

Thanks for the reply; my Voltmeter is one of these



Has two rear terminals, V+ and ground and sits between my I/O box and breadboard.  It works smoothly with my voltage sag knob on all other circuits but the Valvecaster.  Even the 18V 6.5A adapter acts goofy when the Valvecaster is boarded, but it shouldn't even notice the circuit with that much amperage available.  I can't dial it down to 12V, so I've only used the 12V (screechy) and the Boss 9V so I don't cook anything.  Here are my reads;

9V (9.6 on all other circuits, 8.46 on the Valvecaster)

1) 3.58
2) -0.07
3) 0.02
4) 0.03
5) 8.44
6) 5.08
7) -0.04
8.) 0.02
9) 4.21

12V (12.6 all others, 11.68 on Valvecaster)

1) 3.12
2) -0.34
3) 0.01
4) 0.03
5) 11.64
6) 4.75
7) -0.28
8.) 0.02
9) 5.79

The Raw Voltage is measured at the output from the I/O box.  I wonder if I'm getting some inductance in my wiring with all the little voltage readings I'm getting on the pins where everyone is reading 0?  If I pull the tube, everything works normally again, the V-sag knob drop is linear and controlled, put the tube back in and it's chaos to adjust.  I have tried several tubes, all the same results.

[Death Super Mario]

This is my valvecaster soldering.

[juansolo]

It's the thread that never ends!

Anyhow, I've made a couple more valvecasters of late so I thought I should probably post them up.

First up is the 'Philcaster'. Named because it was built for Phil... Who really, really needs to find it (he's managed to lose it!). It's essentially a switchable twincaster with a few tweaks.

Run in a single valve it can be a clean boost or distortion. With two it's just got massively more gain. It also has a bright switch which when enabled can cut out some of the inherent bassiness of the pedal when used with humbuckers. Also of note is that this pedal really sounds best when used after a pedal with a buffer in it in the chain.

It's running a Madbean Road Rage charge pump (the only bit of silicon in the pedal), running the plates at 24v, heaters are running 12v. The valves are NOS RFT ECC82. Unlike the ones I've done running 12DW8's, these don't require anywhere near the current and sound better too.








After building the Philcaster, it turned out so good that I decided to re-visit one of my old valve pedals. So this is essentially an old pedal re-used and re-finished.

I've gone for a single valve pedal as I still have my old Twincaster for double valve excess. This has more grunt than the PC does in single tube mode so it doesn't really clean up as well as the PC does.

So what's different? Well quite a few of the values are for a start to make this more simple than the much more tweakable PC. All the components are mounted directly to the socket to minimise noise from cables going backwards and forwards to the boards as with previous versions. The gain no-longer adjusts the bias of the valve, instead working between stages. Theres a buffer on the output and theres Madbean's Road Rage providing 15v to that, 23v to the plates and 12v to the heaters. It can take a variety of valves, but out of what we had, the NOS Brimar 12BH7 sounded best.

The results are stonking. This is the quietest valve pedal we've made so far and it pushes my new 6V6 MJW 5 watt amp (very clean) into pure AC/DC overdrive. It sounds glorious.

[iccaros]

Thanks for the reply; my Voltmeter is one of these



Has two rear terminals, V+ and ground and sits between my I/O box and breadboard.  It works smoothly with my voltage sag knob on all other circuits but the Valvecaster.  Even the 18V 6.5A adapter acts goofy when the Valvecaster is boarded, but it shouldn't even notice the circuit with that much amperage available.  I can't dial it down to 12V, so I've only used the 12V (screechy) and the Boss 9V so I don't cook anything.  Here are my reads;

9V (9.6 on all other circuits, 8.46 on the Valvecaster)

1) 3.58
2) -0.07
3) 0.02
4) 0.03
5) 8.44
6) 5.08
7) -0.04
8.) 0.02
9) 4.21

12V (12.6 all others, 11.68 on Valvecaster)

1) 3.12
2) -0.34
3) 0.01
4) 0.03
5) 11.64
6) 4.75
7) -0.28
8.) 0.02
9) 5.79

The Raw Voltage is measured at the output from the I/O box.  I wonder if I'm getting some inductance in my wiring with all the little voltage readings I'm getting on the pins where everyone is reading 0?  If I pull the tube, everything works normally again, the V-sag knob drop is linear and controlled, put the tube back in and it's chaos to adjust.  I have tried several tubes, all the same results.

Sorry I must be stupid.. when you connect your voltmeter (your pannal VU )you plug one side into your i/o box and then have no cable, but the other probe is connected to the valve caster?
if so you not measuring volatge, as voltage can only be measured over a load. http://physics-tutor.site90.net/drupal/node/29, that would be measuring current, which If I remember my EE coursed from 20 years ago, a VU will read amp or milliamp in this configuration.


as for voltages, if these are read from pin to ground with tube in, well they are low for the plates.. I would expect 7 volts or so, are you running this through a voltage regulator, and why are you running it off a SAG power supply, the last thing we want in a starved plate design is low battery simulate, which is what your sag is doing. .That is cool on some old effects pedals, but kills head room on this pedal.



as for 

[iccaros]

@juansolo

Good work

I was going to change the gain to a 10uf attached to a 50 - 100K pot. With a 50K (47K) to ground

what did you use for the art? I am thinking of using the tee shirt iron on stuff..

also where are people getting those chrome washers for the tube protectors.. I have been to several hardware stores and can not find any large enough.

[juansolo]

I get asked about the decals a lot so did a how to page.

Tube protectors came from a blokey in HK on ebay IIRC.

[CheopisIV]

Sorry I must be stupid.. when you connect your voltmeter (your pannal VU )you plug one side into your i/o box and then have no cable, but the other probe is connected to the valve caster?
if so you not measuring volatge, as voltage can only be measured over a load. http://physics-tutor.site90.net/drupal/node/29, that would be measuring current, which If I remember my EE coursed from 20 years ago, a VU will read amp or milliamp in this configuration.


as for voltages, if these are read from pin to ground with tube in, well they are low for the plates.. I would expect 7 volts or so, are you running this through a voltage regulator, and why are you running it off a SAG power supply, the last thing we want in a starved plate design is low battery simulate, which is what your sag is doing. .That is cool on some old effects pedals, but kills head room on this pedal.

Lol, no, i doubt you're stupid.  I think i just described it wrong!  It sits in parallel between my I/O box and the breadboard, There are two wires into it (V+ and Ground) and two wires out of it to my breadboard (V+ and ground).  The purpose of the 'sag' knob is to dial my 18V adapter down to 12V (or 9V, etc), not to starve the Valvecaster.  It works perfectly on any other circuit, but the Valvecaster acts funny.

An interesting thing happened and I think (hope) it's the issue.  I was checking to make sure none of my components were touching each other and when I wiggled the input cap, i heard a scraping noise.... This breadboard has a metal plate on the bottom and is supposed to have a shield between it and the board, so I shouldn't have heard the scraping sound.  I think I have to rip it down and check my board... I'm thinking there may be something grounding out under there.  As soon as I get the time, I'll have to rebuild.  Thanks everyone for the comments and tips.

Beautiful pedal a few posts up too!  I love seeing other people's creations!

[iccaros]

I get asked about the decals a lot so did a how to page.

Tube protectors came from a blokey in HK on ebay IIRC.

Thanks, wet stick is really just making me angry, so I will try this, the other thing I was going to try were black tee shirt iron on..

[ThunderShowers]

I'm assuming the all alike wiring colors is to drive people like me mad, and so that people (also like me) can't figure out how you've gone and done it.

Beautiful work though, amazingly tidy.

That Aside, If you don't mind me asking, is that bright switch adding a bypass cap to a cathode, or changing a coupling cap or...?

[zambo]

Those are pretty!

[juansolo]

@ Thundershowers

The bright switch changes the input cap as it could get a tad dark with humbuckers. The boobtube has an in-between input cap to compromise. 

The all one colour wiring is because that's the 100m reel of wire that I'll have been using at the time I ran out of purple and am now on orange.