My Peavey Bandit is especially sensitive to my cell phone. The cell phone "checks in" with the tower from time to time and it can be heard through the amp. Move your cell phone or amp at least 20 feet away, or turn your cell phone off as soon as you hear the noise.
There are 3 major cell phone providers in my area. It is only mine that causes a problem.
Next move, or turn off you computer.
Next change you instrument cable,
next move your guitar away from the amp while playing.
Eliminate the easy stuff first before messing with your tubes.
