Author Topic: ZW-44 With a Gain Problem  (Read 635 times)

latestsaint

ZW-44 With a Gain Problem
« on: February 17, 2019, 10:39:55 PM »
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

Re: ZW-44 With a Gain Problem
« Reply #1 on: February 18, 2019, 09:07:55 AM »


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

Re: ZW-44 With a Gain Problem
« Reply #2 on: February 18, 2019, 08:10:49 PM »
> What would cause the gain section not to work?

R4 C2 broken.
  • SUPPORTER

antonis

Re: ZW-44 With a Gain Problem
« Reply #3 on: February 19, 2019, 04:02:47 AM »
If not what Paul said, check for short C12..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..