Humming transformer?

[Chuck King]

Does a humming transformer indicate a terminal condition? I have a GK bass combo and the power transformer hums whenever it is plugged into the wall---even with the power switch off, which is a DPDT switch that cuts both sides of the circuit.

I read something somewhere suggesting that the transformer needed to be potted---does that make sense?

Is this something that can be fixed, or is it just on the downward spiral?

[donnyjaguar]

Its not possible for the transformer to hum unless current is passing through it.

All transformers hum. If they are humming louder than normal it could just be that some of the laminations are loose. Sometimes you can cure this by tightening the bolts that hold it together. It could also mean that its being called upon to provide more current than it was designed for which usually results in failure. The solution to the latter is to determine what other part of the amplifier is defective and drawing the excessive current.

[Chuck King]

It's humming when plugged into the wall but with the power switched off on the amp. So there is current running through it, but none through the actual amp circuit. I haven't noticed that it gets particularly louder when the amp is in use, but the amp itself is kind of noisy. It definitely needs new filter caps and maybe some other stuff as well, but the transformer hum is independent of anything in the amp circuit.