Yeah I know I know--why bother? But I'm curious. The darn thing shoots up to 20 DC with load as soon as I start cranking the knob.
Opened it up--no solid state. The 50 ohm rheostat checks out OK on my ohmmeter--a gradual 0-50. There are two silicon rectifiers in the circuit. The DC track voltage comes out of the transformer center tap. Also the AC accessory line uses one of the rectifiers. Why?
I plan to convert this unit to electronic anyway but it's puzzling me why the voltage goes so high and fast when the rheostat checks out good.
Any advice appreciated if you have a few idle minutes.
Robby