Print Page - ZW-44 With a Gain Problem

Title: ZW-44 With a Gain Problem
Post by: latestsaint 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

Title: Re: ZW-44 With a Gain Problem
Post by: patrick398 on February 18, 2019, 09:07:55 AM

(https://i.postimg.cc/21HZkD1J/img-1.gif) (https://postimg.cc/21HZkD1J)

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.

Title: Re: ZW-44 With a Gain Problem
Post by: PRR on February 18, 2019, 08:10:49 PM

> What would cause the gain section not to work?

R4 C2 broken.

Title: Re: ZW-44 With a Gain Problem
Post by: antonis on February 19, 2019, 04:02:47 AM

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

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DIY Stompboxes => Building your own stompbox => Topic started by: latestsaint on February 17, 2019, 10:39:55 PM