ZW-44 With a Gain Problem

[latestsaint]

Hey there,

I have a MXR Custom Shop ZW-44 that has internal trimpots mounted on the inside for the gain, tone, and volume.  The volume and tone seem to work well, but the gain pot does nothing.  I measured it with a meter and the pot works as it should.  I also tried replacing the diodes and the opamp itself... still to no avail.  The pot sounds the same at both ends, but when turned in the middle a small change can be heard.


What would cause the gain section not to work?  TIA

[patrick398]

That'll help peeps...assuming it's correct.

I'd check for continuity between pin 7 and 1 end of that 33k resistor. Also the other side of that 33k and 1 side of the trimmer, and the other side of the trimmer and pin 6.

[PRR]

> What would cause the gain section not to work?

R4 C2 broken.

[antonis]

If not what Paul said, check for short C12..