faint signal at zero volume

[jreese2001]

Hey everyone,
I am troubleshooting a home-built AB763 Super Reverb.

I can hear a faint signal coming through the amp when the volume is at zero. I have double and triple checked the wiring in the amp but I am wondering if I missed something that is allowing the signal to somehow bypass the volume control and get into the later stages.

Is there a typical explanation for this behavior that I can check?
Thanks !
Josh

[52 Bill]

Try grounding the wiper/grid connection of the volume control with a jumper wire. If the signal goes away, the pot is not zeroing.

If the signal continues, then I would guess that there is some leakage happening somewhere in your layout. You can try grounding out the signal path through a cap at various stages to see where the signal is coming from.

[Enzo]

It is called crosstalk, and unless it is interfering with the function of the amp, I wouldn;t consider it a problem.

The earlier stages of the amp are making signal, and that radiates aropuns inside the amp. So when you turn down the volume - which is really in the middle of the amp - the parts of the amp after that copntrol have enough gain to pick up that feeble radiated signal and send it to your speaker.

[Twist]

Also try swapping out the pre amp tubes.