Marshall JCM 25/50 Low Volume & Distorted

[mac dillard]

Did this issue get resolved? Been following to see what the actual problem is.

[Aerostoon]

JCM25 50 Jubilee.pdf
I got a chance to get back to the amp and what I did was take all of the AC measurements on all the 12AX7 tubes with a 1kMHz 100MA signal with the volume knobs at max. Power tubes removed. The second plate of V2 is putting out 40VAC. Does that seem high to anyone?

I attached an updated tube measurement chart with the AC voltages indicated in red font.

[dstrat]

Possibly due to the power tubes being removed / is raising the preamp voltage, has there been any other changes since the last voltage chart?

edit: ok went back and reviewed first voltage chart so voltages are the same looks to me so that said
what has changed?

So what does it sound like now?