[Steve Chambers]

Hello Gary,
I did a quick-look over at nostalgia-airs tube diagrams. If their tube substitute info is correct, the #77 tube & #36 tubes wont interchange.
Since your sockets orig, perhaps replacing the #36 w/ a #77 tube will get you going.

If you have a GE tube manual, check the pinouts of the orig #77 tube socket against the diagram in the manual, to that of the schematic. Sounds like someone tried to retrofit a #36 where it doesnt belong?

Substitute tubes for the #77 are listed as a #57 tube, or a 6C6. If you have a spare #57 or 6C6 around, you could check the tube manual diagram and sub them in as a reference.

Best of luck with your restoration!!

A 57 won't work. 2.5 volts on the filament. 77 or 6c6 would require a socket change. Maybe Ron or Chuck can explain the documentation mystery.

Steve Chambers