Hi All,
well, I didn't have as much time as I wanted, but, I was able to add an opamp in front of the tube to drive it harder. Boy does this make the poor tube cry :)
Anyways., here are two clips, one clean and one dirty. Adding the opamp (1/2 of a TL072) in front of the tube made this little sucker LOUD (for 12v, it is very impressive!!!). I am suprised at how quiet the amp is! Anyways, sorry for the bad sound quality of the clip and even more sorry about subjecting the entire internet to my shameful guitar playing.
Here are the links:
http://www.geocities.com/slajeunesse/clean_clip.mp3
http://www.geocities.com/slajeunesse/dirty_clip.mp3
As they are on geocities, there are a few things:
- You need to cut and paste them in a new browser window
- You might get an unavailable message because I exceed bandwith limit
Anyways, once I have more time, I will add to the design and I will post an updated schematic.
This is getting very interesting.
Cheers,
Stephane.
hey slajeune, isn`t it a bit dangerous these days to play funny names/games on that "puretube" company these days?
QuoteBoy does this make the poor tube cry
Sorry Lurco, but, I fail to see how that sentence can be taken in a wrong way?
[sarcastic on] are we allowed to use "wrong way" in a sentence, as it could allude to not doing the right thing and therefore alluding to incompetency and therefore being politically incorrect [sarcastic off]
I think that we need to chill a bit.
Stephane.
no fear, slajeune: I love the word-symbology
(or whatever people round the world would like to call it)
between "poor" and "pure" -tube, and how it can cry
(.. maybe `bout the bad-a*sliness of the world?)...
To clear all doubts (if any existed), I was talking about the 12ax7 tube being pushed into distortion. Period. End of story. Let's move on with our lives people, life is too short to twist what each other says.
Enough said.
Stephane.
For what it's worth, my mother tongue is french and not english, therefore, somethings might be lost in the translation.
i thought he was talking about ruby tuby ie ruby tubes... did i miss something here
Hey Ansil,
hum, hadn't thought about that one. See, I'm over-reacting... Classic symptoms of somebody that really needs a vacation. Ahhh, 2 more days and I'll be on a beach.
Ansil, did you hear the clips? What did you think of it? It's a first shot at it, there are so many things that I want to do with it when I come back from vacation. A simple tone stack is the first on the list.
Cheers,
Stephane.
sounds cool to me.. you can use a lm386 to slam the input instead of opamps.. gets more bang for your buck..
Stephane,
Congratulations on getting that build up and running. I know how hard you worked on it. I admire your perserverance...man, you were NOT going to let that get the better of you.
It also goes to show how valuable Puretube and The Tone God are to this site. That's a great thread that the 3 of you worked through.
I haven't heard the clips yet...the site won't load right now.
Doesn't matter...
I'm very happy for you.
Great job.
Sounds pretty neat for a starved tube! :D Are you gonna post any schemmo's or not? Or have I missed something :?
sounds pretty good...
i missed the poor tube thing at first too, didn' think there was any negative intentions on that...
what beach ya going to? i could do with a vacation
Hi all,
csj, thanks for the great words of encouragement. You also helped me, so a big thanks to you to! I hope that that thread will help others.
Smoguzbenjamin, there is a priliminary schematic that can be found here:
http://www.geocities.com/slajeunesse/ruby_tuby.pdf
This one doesn't yet have the opamp in front to overdrive the 12ax7. It is very simple to add, it's a simple non-inverting opamp section with a crontrolable gain. Very very similar to what you find in a MXR Distortion+ pedal.
Sic, thanks for the nice words! I'm going to the Bahamas!!!
Ansil, I like the idea of using another LM386 because I can get rid of the voltage divider for the opamp. I'll definately look into that when I come back from vacation.
Cheers,
Stephane.
Quote from: slajeuneAnsil, I like the idea of using another LM386 because I can get rid of the voltage divider for the opamp.
...but if you add a TL072, won't that mean you'll have to add the voltage dividing crud? Although I guess that means you could use 1/2 of the opamp to drive the tubes and the other half to replace the LM386...or am I missing something?
P.S. Finally, something with a tube that's simple enough for me to build! :o
Hi Bobbletrox,
yes, if you use any ordinary opamp (tl072, lf353, lm741) you will have to use a divider network. Not a big deal, but, it adds to the total number of components. Using an LM386, you don't have to use a divider network (it's internal to the LM386). You can't use the second part of the TL072 because it isn't a power amplifier. The LM386 is a power amplifier and therefore is a good fit. I used a 1/2 of a TL072 because I had one lying around. Any single opamp (even a lowly 741, althought it will be noisy) will work to push the 12ax7 into distortion.
Having said that, be sure to use an LM386-N3. I used an N1 and the voltage of the entire circuit droped to 9v (which is not enough for the heaters on the tube).
BTW, this is my first circuit that deals with tubes. My goal was to make the design as simple as possible (hence the use of the LM386 for the power amp portion). I also wanted to power the amp with a simple wallwart to make it even safer to build (a power transformer is connected directly to 120V). I think that I achieved these goals with a lot of help from The Tone God and puretube. Filtering / regulating the power supply was the key to make this thing work!
Cheers,
Stephane.
Oh ok! ...the 386 is a power amp :oops:
Btw, those clips sound great. Did you record them direct into a soundcard or through a speaker cab?
Hi bolbbletrox,
No problem about the LM386, I thought that it was just another opamp when I started using it.
I plugged the speaker of my Gibson GA-15rvt into my ruby tuby, so, I am using the cabinet of my gibson amp (1x10 inches). I have a small ZOOM PS-02 (multi-track recorder) that has a builtin mic. I simply miced the speaker. The mic isn't the best one, but, I guess it gives an idea of the sound that the ruby tuby produces.
It does sound clearer in reality!
Cheers,
Stephane.
you know looking at this a little further it wouldn't take much to add in the voltage doublign ladder paia uses in the siab amplifier
http://www.paia.com/siabsch.pdf
Hi all,
Ansil, hum, that looks very intresting, I might look into it after my vacation. What would doubling my B+ to the 12ax7 do? I guess it would add more 'headroom'. Might be another cool modification to do.
While I'm on the subject, I tested a few things today:
- Added a volume control right before the LM386 and it is very nice! Now I can have a cool distortion without the amp being to loud
- Added a very simple tone control
I don't have time to modify the scheamtic for the amp before I leave, but, once I'm back, I'll update the updated schematic.
Cheers,
Stephane.
well i am not sure theoretically what doubling the b+ would accomplish i assume more headroom. but if you were to take it to around 50+ volts it is supposed to be pretty cool sounding. i think the paia uses like 48v or so on the ubes.. and according to a few articles i have read about the evh dropping the the voltage to like 90v on his variac and gave him some seriously creamy brown sound. but i am not sure what the b+ was after this. he posted values and i tried it once via a home made preamp that i altered the b+ to what he measured his at when he dropped the voltage.
i am not sure if it would hlep ya or not.. of course you could just build a tube amp... lol
or instead of the lm386 add a 20 v power supply and use a lm3886
Whatabout the tube heaters? Do you feed em 12vdc just like that or leave them out alltogether?
Great stuff Steph. I'm happy to see your pleased with the results thus far. I'll breadboard up the preamp and see if I can tweak some values for you to try out after I'm done with my current tube project. I have gotten a 12AX7 to distort nicely at 12v without a frontend preamp.
Quote from: Ansilwell i am not sure theoretically what doubling the b+ would accomplish i assume more headroom. but if you were to take it to around 50+ volts it is supposed to be pretty cool sounding. i think the paia uses like 48v or so on the ubes.. and according to a few articles i have read about the evh dropping the the voltage to like 90v on his variac and gave him some seriously creamy brown sound. but i am not sure what the b+ was after this.
Thats kind of an old trick but double the voltage won't do much at this point. Nothing special will happen until you hit 100+ volts. I think that is beyond the scope here.
Just a word to any EVH wannabes, the variac "trick" on any tube amp is stupied and wrong. Don't do it, period.
Andrew
I know what doubling the voltage would do...
...it'd give me twice the electric shock if I make a mistake.
Hi All,
smoguzbenjamin, if you double the voltage, the heaters must still get 12VDC (in the current design).
Bobbletrox, 2 times the shock but at 24V, it's not going to be painful! Maybe a slight tingle.
Andrew, can't wait to see the result of your experiment with the preamp section! If it can make the design simpler, it would be better! The goal is to have a small practice amp that is easy to build (the less amount of parts as possible) while having a good sound and using a tube to get the distortion sound!
Hopefully, people will be able to build it easily.
Ok, see all of you in a week!
Cheers,
Stephane.
Great job guys! 8)
I'll agree with Andrew that the "magic" really starts over 100 volts, but 50 volts and 12 volts have different textures. The big question for me is does the different tone at 50 volts justify the extra complexity of a DC/DC converter?
You should try as many different 12AX7s in there as you can get your hands on. The difference between a tube with small plates and large ones is beyond amazing. In that circuit, I think you'll find the sound of an Ei ECC83 (BIG plates) and a Sovtek 12AX7WA (small plates) will be remarkable.
I have a PAiA "Tube Head" which also uses a 4049 converter like the stack in a box, but it uses larger caps (33uF instead of 1uF) and is able to deliver about 45 volts. http://www.paia.com/tubehsch.pdf That circuit uses BIG resistors on the plate and cathode just to accentuate the staved effect a bit more.
It's worth experimenting with and the voltage is still low enough to not be an issue for shocks.
I really like the tone on that dirty clip. 8) Uh huh huh huh
Take care,
-Peter
This sounds like the perfect way for me to get into tubes (finally). One question, what kind of guitar was the clip recorded with?
It seems like times are getting grayer: check out this thread before it`s gone through the "almighty" censorship:
http://acapella.harmony-central.com/forums/showthread.php?s=&threadid=571576
Perhaps a dumb question, but is there a way to use that schematic as a basis for a tube distortion pedal instead of a tube small wattage amp (I.E. use the output perhaps before it gets to the LM386)? Only reason I ask is it looks doable for a dolt like myself to build, cuz I'd sure like some tubes in front of my tube amp to get that bluesy funky distortion. Thanks.
Regards,
Lone
Quote from: Lonehdrideris there a way to use that schematic as a basis for a tube distortion pedal instead of a tube small wattage amp (I.E. use the output perhaps before it gets to the LM386)?
Regards,
Lone
Absolutely.... just use a pot instead of the speaker and there you go :D . The value isn't too important. Use whatever you have on hand and take your output from the wiper.
I wonder how much of the distortion is from the tube and how much is from the 386? It's a nice recipe in any case.
Another starved tube design is floating around out there from Ron Black. http://www.music-lounge.com/schemas/tubedist.pdf That one uses opamp buffers on the front and back. I built it a number of years ago but wasn't too happy with the resulting sound. More good stuff here: http://amps.zugster.net/articles/tube-pedals/
Take care,
-Peter
So essentially build it as is and use the output pot to control the amount of desired gain going to the guitar amp input (if so that rocks, tube distortion without ear bleeding hehe) :) ? Thanks for the response BTW. :D
Regards,
Lone
No problem. :)
If you use a 500 ohm pot, you can use it either as a distortion box, or with a speaker connected it becomes a practice amp with an output attenuator capable of bedroom levels. Very cool. 8)
Take care,
-Peter
Hi All,
I am just back from vacation!!! I will post an updated schematic later this week.
Javacody, the sound clips were recorder using a Fender Stratocaster with single coils only (bridge pickup). Therefore, you could get a bit more drive using humbuckers!
Cheers,
Stephane.
Hey Stephine, I may have something for you to play with later today or tommorow. Keep an eye out for it.
Andrew
all 12-volters, check this:
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=19854
Great sounding device, I definately intend to build this one at some point, Guess I'll wait a bit till its finalized, but the first clips sounded awesome, great job. I tried doing a schematic on the first schematic in first expresspcb and then eagle (eagle was easier as I had the tube library off their site) with the intent of then using the PC board function, but then I was having trouble finding input and output jacks (it was nearly complete but that, and the pinouts on the 386 were'nt quite like the schematic, something I could have fixed). I like parts of Eagle, but its not very friendly in a cut and paste sort of way, it doesn't appear to use standard windows drop and drag conventions... Oh well, sorry got off topic, just wanted to say thanks for the scheme and the clip sounds good, nice work.
Regards,
Lone