In my limited testing I found that the volume pot had completely seized. It had been very stiff and a nice application of contact cleaner/lube didn't seem to help. It's a double pot for reasons I can't figure out looking at the schematic.
While we're on the subject of schematics, this amp has two 12AX7 tubes, but from what I can see each is only using one of the dual triodes, with V1-a using triode #1 and V1-b using triode #2. What's the reasoning for not using both triodes in a single tube? Ease of wiring? Lower Noise? Making people buy another tube? :tennis:
Also I can't seem to find a replacement for that pot so far and looking at the amp I don't think it's going to be fun to replace if I do. :moody: