The Steel Guitar Forum

My twin reverb makes a humming noise that goes away when i turn the treble and the bass knobs to off,is this the pots or something else?
Thanks Clint

Clint mine does the same thing until I turn the reverb knob down. So I am wondering the same thing.

Craig

Hello Clinton
Both channels hum ? Only when an instrument is plugged in? Normal for there to be some hum when the reverb control is turned up.
Faulty pots wouldn't be my first guess. A bad preamp tube more likely. Jerry

It hums with or without an instrument plugged in. will probably have local tech check it out.

Fender amps have a tone stack, if you turn the treble, bass and mids to zero the output is severely diminished. You need EQ. The hiss didn't go away, it's still there, you just can't hear it due to the volume drop.

Clinton Zimmerman wrote:My twin reverb makes a humming noise that goes away when i turn the treble and the bass knobs to off,is this the pots or something else?
Thanks Clint

Hey Clint,

Found your post and wonder if you solved your hum issue. I've worked on many Fender tube amps and occasionally there's one that will hum more than the average....I usually end up resolving all the hum out of the signal path with various methods. It can be done and most folks like that. Sounds like it was in the front end....goes away with the channel vol pot off, right? If it does, then it's an issue with V1 or V2....Chan 1 or Chan 2. If you change out the suspect preamp tube with a known good one (important) and the hum goes away, then that's it; if not, then measure the frequency of the hum...I expect it to be 60hz and let me know. Hope that helps

Thanks terry I will try it.
Clint.