If you can find a good guitar amp repair shop locally they may be able to help you.
Need help finding spec. sheet, schematic, and or manual
For an earlier Sophia Electric Technology EL34 amp.
I have this: https://www.diyaudio.com/community/threads/sophia-electric-el34-schematic.155095/
and this
https://www.audiocircle.com/index.php?topic=108577.0
Sophia says they have no documentation since the amp has been discontinued.
They also, b.t.w. refuse to work on it because they're "too busy".
Imagine McIntosh acting like this.