CARVIN MTS3200 HELP!!! loud hum noise

[brian_shott]

I currently have a Carvin MTS 3200 Master Tube Series Combo amp and for some reason randomly the clean channel is overcome with a LOUD! hum noise. You cannot hear the guitar anymore and the loud hum noise is unbearable and i have to shut the amp off immediately because its so loud. While this is happening I checked switching to the distortion channel and it's fine, you can hear the guitar but you can also hear the hum slightly in the background. It only happens on the clean channel and happens randomly during play (sometimes 15 minutes into using the amp, and sometimes when I turn it on). Anyone have any suggestions as to what this could be?! its very frustrating seeing as I start playing gigs in a month.

[Enzo]

I don't know the amp, but if the preamp is tube based, then I'd be swapping preamp tubes around to see if I had a bad one. Otherwise I'd look for grounding isssues like lose connections and wires off jacks, etc.