Bandmaster Reverb arcing rectifier AA768

[Mr_bibbles]

The "off" position is what matters here (though it's confusing). When the switch is closed, the meter will see no current.
Anyway 97mA looks too high.

Great thank you for explaining! that I will try and hone in what could be causing that.

Also..... the reverb transformer is vibrating slightly??! Is this normal? I can tell it's the reverb transformer because I hold a pencil lightly to it and it vibrates up my hand, like the intensity of a tiny electric motor. I can touch the pencil to the other transformers but it's strongest from the reverb.

[Helmholtz]

As the amp seems to have separate 150R cathode resistors, it's easy to read individual idle currents.

[Mr_bibbles]

For anyone still looking; Turns out the output transformer was arcing intermittantly. Very tough to find, but by giving it a hard poke with a chopstick I could read voltage fluctuations off the blue OT tap, even when unplugged. Those variations accompanied noise and hard current pull so it solved all our problems to replace the OT!