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.
I was given a pair of Ampex 6973 mono block amplifiers. Should I install a three prong AC cord that grounds off the chassis or stick with a two prong cord?
Install three conductor power cables and ground to the chassis. If there are caps to ground on the AC primary, remove or replace with AC safe caps (they fail open).
Always best to have the chassis at ground potential. If you get hum issues, use a 10R 2W5 resistor (that has a 1nF cap and back to back 1N5401 diodes across it) in series with the Earth conductor in the chassis end, that will ensure coupling for safety to ground but allow for earth loops.
Always best to have the chassis at ground potential. If you get hum issues, use a 10R 2W5 resistor (that has a 1nF cap and back to back 1N5401 diodes across it) in series with the Earth conductor in the chassis end, that will ensure coupling for safety to ground but allow for earth loops.
