12AU7 preamp + overdrive on 12V

[Isak]

Hi guys.

I need an advice or Guidness.
I build the valvecaster overdrive tube, I pretty happy with it but it's not great for synth use, I actually don't use it for guitars.
One of the forum memebers told me cause it's working with 12V the input signal should be very low.
it's true! When I lower the vol pot it's sound very very good, with a lot of bass but still very good.
I put a preamp at the output to have a higher output, work good.
I was wandering if I can save the preamp module and add it via one of the tube stages.
Meaning one stage of the 12au7 to give me an overdrive and the second stage to give me a preamp.
Or maybe have an preamp that makes overdrive.
I hope I'm making sense.
If its possible I wish to know how to do it.
It have to be simple like the valvecaster is and running with 12V.

I thank you in advance.
Isak E.

[duck_arse]

if you put a switch between the 2 stages, you can switch between take the output of the first section as your low-level out. put your preamp after the switch and in front of the second stage for your high-level output.

that's if I'm understanding correctly. and explaining clearly.

[Isak]

Thank you for replying.

I think I didn't explain my self very well, sorry about that.
What I want is to get a preamp and overdrive from one tube (12AU7).
I was looking for simple scheme that give me overdrive from one stage of the tube and preamp from the second stage or backwards, preamp first and overdrive second.
I don't want to use an external preamp module, I want to use the tube as preamp and overdrive.

I hope I explain my self better this time

Cheers.

[duck_arse]

you might be able to replace R4 with a 500k pot, and take its wiper to a switch, then you could switch between the first (pre-amp) stage output, and the second (distorting) stage output. swapping R2 and R3 may also help.

I don't know that this will work, but it might be what you want.

[pinkjimiphoton]

how about adding a diode clipper from the output of stage one feeding the input of stage two?
hey, it works in stompboxes.. try a couple 1n4001's or something maybe? inverse pair 'em  to ground after the output/coupling cap of the first stage.
maybe try putting a pot between the clipper and ground wired as a variable resistor to ground for a bit more control over the clipping threshold.
i bet you can get something that will work. you could even put a switch in to take the clipper in or out of the circuit for cleaner or dirtier.

[iccaros]

Hi guys.

I need an advice or Guidness.
I build the valvecaster overdrive tube, I pretty happy with it but it's not great for synth use, I actually don't use it for guitars.
One of the forum memebers told me cause it's working with 12V the input signal should be very low.
it's true! When I lower the vol pot it's sound very very good, with a lot of bass but still very good.
I put a preamp at the output to have a higher output, work good.
I was wandering if I can save the preamp module and add it via one of the tube stages.
Meaning one stage of the 12au7 to give me an overdrive and the second stage to give me a preamp.
Or maybe have an preamp that makes overdrive.
I hope I'm making sense.
If its possible I wish to know how to do it.
It have to be simple like the valvecaster is and running with 12V.

I thank you in advance.
Isak E.

IF I get what your asking (for more headroom, or more output because turning down the synth is too quite) then no.. but yes.. the problem is 12v... if you use a simple voltage multiplayer and go to say 80v.. you may get more of what you are looking for.  there are several posted on the page, I can send a schematic if you want, I don't do layouts..