Is this a guitar amp? or designed for normal audio listening?
You can remove the pot by placing a resistor from grid to ground, then you are driving the grid directly. Not the best design. Options are add a small (10K series resistor on the input, or add a coupling cap.
What are the tubes?
Your gain going to be pretty high with the second stage cathode bypass. I'd be inclined to leave the gain pot in place.
Others are more familiar with DHTs and such stages and may have more insight.
You can remove the pot by placing a resistor from grid to ground, then you are driving the grid directly. Not the best design. Options are add a small (10K series resistor on the input, or add a coupling cap.
What are the tubes?
Your gain going to be pretty high with the second stage cathode bypass. I'd be inclined to leave the gain pot in place.
Others are more familiar with DHTs and such stages and may have more insight.
replace it with a 100k resistor to ground. I would consider a small grid stopper of about 1k though.
Gimp makes some valid points as well.
Gimp makes some valid points as well.
A Walton Audio design. Tubes are 5692 and 300b. I have finished one mono block. I use my computer to play mp3 and have noticed little volume increase and poor clarity from the computer source. Basically I turn volume up 100% and I get poor gain and sound quality. When I use my line stage/preamp, things sound great.
I don't know what computer/sound card you are using, but my Mac Mini audio output is about 1/3 the level of a typical CD player (mine also suffers from induced noise from the big LCD display, a common problem afflicting Mini's).
Either way, you are not going to solve the level problem by removing the volume pot unless the computer's expected load impedance is way higher than the pot value.
Ooh! Just had a thought! If you don't have a coupling capacitor on the amp input before the vol control, maybe the computer has some DC on the output line (and your preamp doesn't). It wouldn't take much DC getting to the amp's first stage grid to really mess things up.
Cheap volume pots can noticeably affect square waves on the scope, I try and remove where possible. As mentioned already, a 100K across the input terminals, with a 1K to the input tube, will be an improvement.
However in this case it does sound like the source is the problem.
However in this case it does sound like the source is the problem.
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