• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Fisher 440 Restoration/ rebuild

I rebuilt a Fisher KX-200 a few years back. The rebuild involved replacing all the capacitors, changing resistors to a different value so the tubes lasted longer (lower amperage through the tubes), rebuilding the switch/volume control. I would say it took about 20 hours working slowly and methodically.