Output volume inconsistent problem, unexpected spikes

[johnmfer]

I have a RM50 combo, silver grill cloth, no reverb. The problem I'm having is after the amp has warmed up, the volume sometimes spikes up at random to a higher volume. When it first happened I thought it might just be the output tubes going bad and replaced them with some brand new ones. The problem persists, though. It happens with both modules, so I know it's not a bad module.

Last night it happened while I was playing, and I tried putting the footswitch in the master volume boost footswitch jack, thinking maybe the jack was going bad and causing these random boosts. The amp popped and fizzled for about ten seconds and then I didn't have any more problems. I'm not sure if putting the footswitch in solved it, or if the problem went away on its own coincidentally.

Anyone experienced a similar problem? Anyone have any other ideas what might be going on? I have no use for the master volume boost footswitch jack, maybe I could just defeat the jack with a 1/4" plug attached to nothing?

 

[Scooter]

Do you run the master volume way up and adjust your stage volume with the individual module's volume? Probably not. All the volume boost jack does is max out the master volume when engaged. If you're already running at or close to max, then the volume really couldn't spike.

Of course this would just be a band-aid. I'd like to know what's causing the root problem. :?

 

[johnmfer]

That's not a bad idea. I haven't really tried that. I would prefer to have a master volume, though.

 

[johnmfer]

I tried this out a couple days ago, it sounds quite a bit different and I didn't care for it. Anybody have any other suggestions? Anybody else have this problem?