So today while I was playing on the red channel there was a problem with the power @ my place, it quickly went out and back on - and there it was, no sound came out at all from the red channel. Green and blue channels seem to be fine. When I'm on the red channel, there is no noise whatsoever, only very dim white noise. Even when the jack isn't plugged into a guitar, there seems to be no noise at all, no buzzing when I place my finger over the jack. Is it only a preamp tube problem or could it be worse?