HUNT AMPLIFICATION

Someone had replaced the power transformer in this amp, but didn't install a virtual center tap for the heaters.  By some stroke of luck, one side of the heater winding was grounded through messy wiring on the pilot light (preventing any hum) - at least until it jostled loose - then the amp hummed LOUDLY.  I cleaned up the PT wiring, installed the missing center tap, and replaced the screen and control grid resistors.  Don't see too many original AA864s like this.