Ruby Tuby Sound clips posted!

[The Tone God]

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.

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.

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

[bobbletrox]

I know what doubling the voltage would do...

...it'd give me twice the electric shock if I make a mistake.

[slajeune]

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.

[Peter Snowberg]

Great job guys!

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. Uh huh huh huh

Take care,
-Peter

[javacody]

This sounds like the perfect way for me to get into tubes (finally). One question, what kind of guitar was the clip recorded with?

[Lurco]

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

[Lonehdrider]

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

[Peter Snowberg]

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)?
Regards,
Lone

Absolutely.... just use a pot instead of the speaker and there you go . 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

[Lonehdrider]

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.

Regards,

Lone

[Peter Snowberg]

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.

Take care,
-Peter

[slajeune]

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.

[The Tone God]

Hey Stephine, I may have something for you to play with later today or tommorow. Keep an eye out for it.

Andrew

[puretube]

all 12-volters, check this:
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=19854

[Lonehdrider]

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