Fender Super Headknocker

[Gtr_tech]

Ok, I guess I didn't read carefully enough then. Standby switches can get pitted contacts from acring and that will cause them to be noisy. If its a specific tube that is associated with the noise then you need to do some poking around in that tube's circuitry.

[Enzo]

If pulling V5 kills the noise, then the noise is coming from the V5 circuit or before that point in the circuit.