Music Man 1650 RD channel switching problem?

[pontiacpete]

This morning while still a concerned over the voltages being so different, I took another look at my installation of the new transistors I put in place of Q3 and Q4.
Sure enough I screwed up the installed, got the collector and emitters backwards on the board. I pulled the 4401s and got some 3391s out and put them in correctly and the voltages are now acting in line with the schematic, Q3 collector changes from -7.4 to +4.9 and Q4 changes from 7.4 to -7.4.
Now it's working for certain. Can't believe i got the pinout wrong the first time around, but glad to have solved the problem.
Thanks again for the support, it is much appreciated!!

[J M Fahey]

Cool, way to go.
I suspected something like that (the second possibility being internally shorted switching gates dragging control voltage down) and if you hadnīt solved it by now, I was about to suggest you protoboarded the 2 transistor switcher/inverter "outside" the main board so it could be tested without other (bad) parts interference.
But all is well if it ends well

[pontiacpete]

This amp is back,, kind of too soon in my opinion. Now it's switching from limit channel to clean all on it's own. Checked switch again by unhooking and shorting the wires. It's definitely doing it on it's own. Re-soldered board, cleaned IC sockets and banged on all components.