Have you ever had this?

[rutledj]

On a basic fender preamp ckt I have a problem where when I turn the vol all the way down it gets a bad low level hum. Turn it up just a fraction and it goes away. I've replaced the pot to no avail. Everything else works great and the amp sounds great.

Any ideas?

Rut

[iknowjohnny]

Sounds like an iffy ground. i'm sure you probably already eliminated that, but if not run a clip wire from the ground lug of the pot to various ground points and see if any of them stop it. Thats what i'd try anyways.

[rutledj]

Yep. Checked that. It is actually more of a buzz than a hum.

[jjman]

Does it happen both with and without an instrument plugged in? At all volume knob setting on the guitar?

[rutledj]

Actually, I found it. It was picking up a signal (somehow) from the wire running from the tremolo ckt to the foot switch (for killing the oscillator). When I move it around the buzzing goes away. Alternately, it varies when the intensity or speed pot is adjusted. I'm even using shielded cable for that wire!

I guess I will need to relocate the foot switch jack so it isn't near V1.

Rut