Hey,
I recently purchased a red knob concert lead amp head and I was nothing but pleased with it until about five days later, a very slight static became apparent, so I turned it off and let it set for a bit thinking that it may just need a break. When I turned it back on the sound was quite loud.
I spoke with a far more electronically inclined friend than myself who suggested spraying a contact cleaner he recommended in the input jacks and cleaning them believing that corrosion may be the cause of the staticy sound.
After I did this the problem went away for awhile only to return some time later.
Through some trial and error I determined that the cause of this is the Power Amp In jack, when the sound occurs I can connect a 1/4" jack into it, jiggle it around and the sound will stop for about five minutes or so only to return.
Currently the sound is not occurring and it hasn't been for about an hour.
My first question may seem silly; what is the power amp in jack for?
My second question is what does that have to do with this sound and why does pushing on the contact alleviate the issue temporarily?
Third question; what can I do to fix it?