Tube boost + overdrive running off a 9 volt battery

[duck_arse]

@ psychfush - trick question - can I use a 6J6 (they were cheap here, too) in your srpp circuit?

[timd]

Is there a list somewhere of all the tubes that work well with the original schematic besides the 12AU7? I had a few random 9 pin tubes around and found a 12DT8 sounds really good in the circuit. I was just looking for something comprehensive to take with me for tube shopping!

[psychedelicfish]

@ psychfush - trick question - can I use a 6J6 (they were cheap here, too) in your srpp circuit?

6J6 has a common cathode, so you can't do it with one 6J6, but you could use two 6J6s, connecting the triodes in each in parallel.

[duck_arse]

an interesting idea, but anything taking up that much space would need to be doing a little more work. lord knows, I have enough trouble with "space" as it is.

[Jdansti]

Hi,
I build this effect and it seem that it works, but I have one problem and I would be realy grateful if somone can explain to me, what's goin on.
I'm using this effect for a bass, but I wouldn't say that's the issue. Chain is following: pasive bass -> valvecaster -> lexicon alpha (external PC sound card) -> directly to amplifier (it's not going over the pc), this chain is ok, no problem, everything works fine, but when I use normal amp, in my case it's Trace Elliot GP12 smx here comes problem. Chain is similar, bass-> valvecaster - > trace -> cab, there's almost no change in sound when I turn with any of pots, doesn't react to volume, gain, tone ... nothing, and the result sound it's not plesant, there's feedback from a cab, but when I connect effect to effect loop, it works as it should, why?
I would like to overdrive sound before preamp, it's better for me. So, now I use effect loop, but it's not good.  Thank for all answers.

You may have something going on with the low or high compression. If you don't have a manual, you might want to take a look at this: http://www.britishaudioservice.com/inst/SMX.PDF

[toplak666]

Quick question... How would I go about wiring a twincaster circuit to work with one gain pot?

[peterg]

Stacked pot is one way

[toplak666]

Indeed that would be a way... How are amps wired though? Pretty much all amps use only one pot to controll gain for 4+ tubes.

[peterg]

Check out the Pepper Shredder tube boost or Rick Holt's Super Fly or Murder One amps or the Orange Tiny Terror amp schematics.

The gain pot controls how much current flows from the end of the first stage (first half tube) to the second and further stages.

Good luck with which ever path you take.

[toplak666]

Thanks mate! I'll be sure to check them out. Love the Tiny Terror btw. Hope I'll have enough money for one soon...

[toplak666]

Also, I made this:   

Feel free to use this if you need it. The above image is resized. Save it from here: http://i.imgur.com/WqWRnHs.png
It looks huge but it should resize itself to the correct size for printing if you throw it into Word... Let me know if it doesn't.

[peterg]

Very good. Thanks. That should come in handy.

[Gamel14]

Hello, sorry for my bad English, I'm French.
I have a question, I try to build the Subcaster and I don't know where the middle pin of the trimmer goes. I think it goes to ground but I'm not sure. Can you tell me where this pin is connected ?
Thank you 

[duck_arse]

hello and welcome, gamel. yr english is fine so far.

if you mean the trimmer on the lm317 voltage regulator, connect the wiper leg to the grounded leg, so you get a variable resistor.

[bufferz]

Hoping for some help. I tried breadboarding a stripped down version (no tone control / 10k fixed gain resistor)

I am getting signal at pins 2 and 3 , but ths signal stops there, no signal at pin 1

I am using 9V, with 100k plate resistors, 470k grid leak resistor, i tried a 12ax7 and 12au7




and a schem for easy reference



I hope I am missing somethig obvious. Cheers

[Jdansti]

Hoping for some help. I tried breadboarding a stripped down version (no tone control / 10k fixed gain resistor)

I am getting signal at pins 2 and 3 , but ths signal stops there, no signal at pin 1

I am using 9V, with 100k plate resistors, 470k grid leak resistor, i tried a 12ax7 and 12au7




and a schem for easy reference



I hope I am missing somethig obvious. Cheers

Are you using a battery or adapter?  Check your supply voltage.

[bufferz]

I am using a "one spot" I suspect it may be a power issue as well. perhaps my breadboard is lowering the voltage ..... I will check it out

[bufferz]

Ok, here are the voltages:

P1 -5.2
P2 -7.23
P3 -7.23
P5  9.04
P6 -.63
P7 -.60

fwiw, I tried running it at 12 V using my bbe supercharger and it still didn't work... such a simple circuit - such an epic fail - not a great into to tube circuitry here i'm afraid

[Jdansti]

Ok, here are the voltages:

P1 -5.2
P2 -7.23
P3 -7.23
P5  9.04
P6 -.63
P7 -.60

fwiw, I tried running it at 12 V using my bbe supercharger and it still didn't work... such a simple circuit - such an epic fail - not a great into to tube circuitry here i'm afraid

Are the voltages at pins 1, 2, 3, 6, and 7 negative relative to ground?

[bufferz]

sorry - not sure what you mean exactly, to gather the voltages i referenced above I put the positive tip of the muiltimeter to the respective pin and negative to ground