[Adam]

I think I found my sound problem. Look at this messy soldering on the bottom of the sound module. It looks like it cracked, and somebody tried to bridge the cracks, but didn't do it too good. It's not totally visible in the pic, but it's using this stranded wire which has loose strands touching other traces it shouldn't.

Charles, I'll send a pm about that module you have, thanks.

This is one of zeniths very first solid state chassis, so it's partially modular, and partially not. In some cases transistors plug into sockets on the chassis just like tubes would. It's an interesting chassis, I'll post some pictures of it later.