Guys,
My buddy bought a ‘71 1959 that needs some TLC and I’m trying to help him with it. The amp hasn’t been modded but someone has definitely been in here at some point. I’ve replaced some resistors on the board in order to go from 6550’s to EL34’s, changed the NFB tap and resistor and removed the death cap and installed a 3 prong plug. I’ve double checked the screen filter wiring and it looks right to me but when I went to bias it, I’m long getting like 230 volts at the plate. Tried a known set of good tubes and same thing. I’m at a loss.