I found this manual from 1946 in the drawer at the WICC transmitter site, which is a sort of time capsule due to its inaccessibility. I figured I would bring it home and scan it, then return it to the file drawer out on the island. Step one is done:
This is a cool little monitor amp, capable of driving line level or speaker outputs up to about 10 watts or so. It could be used as a front or input stage for a larger audio amp. By the way, 10 watts is a lot more than it seems, if using efficient speakers to convert that power into sound waves. Specs show total harmonic distortion is between 0.6 to 2 percent depending on power and frequency. Lower power output levels net less distortion.
Schematic is pretty simple, a pair of 6L6’s in push-pull for the output. Inverse feedback into the previous stage via the output transformer. Click on image for higher resolution.
Full manual and parts list is available here.
Now I just need to get the manual back out there.