So yeah, I've had my 2x12 dual rec roadster (4 channel) for awhile now and it has primarily been used quietly in my house.. no problems.. Ive been taking it out jamming as of late and really getting to fire it up... I mean the thing sounds AWESOME now that I have been turning it up and have it dialed in... but last night when I switched to my SOLO channel, there was no difference in volume... I can turn the knob all the way up and there is no change in volume.. any ideas as to what this could be ? A foot swtich problem? Somthing in the amp itself? :?