Originally Posted by
Don
I asked because an old amp might have old filter caps that need replacing regardless of noise plus the old Champs had a power switch built into the volume control which puts the AC really close to your signal which can induce noise. There's a lot going in in a small space in a Champ which can induce noise if you're not careful. The Mojotone tweed Champ clone hums a little. I hear it when I'm alone in my studio but it's not noticeable at all when other people are in the room. Even when we're not playing.
I haven't seen any specific complaints about bad filter caps in these amps. It can't hurt to replace them, though I'd search Google and guitar amplifier specific forums for more info.