I wasnt sure of where to post this as there is no section for this kind of amp. Its a Behringer UltraBass BX600 portable bassamp for bassguitar. I got it for Christmas this year and about 3 weeks ago something made a loud popping noise and the volume dropped drastically. Now when I play a low note theres a lot of rattly distortion and high notes are fairly clear but there is some rattly distortion. Also the volume has to be about twice as high as I would normally operate it at. I have never pushed this thing far enough to blow anything but it would seem something is blown. The volume knob goes to 12 and I usually kept it at 4 because it a 60watt amp and a 12in speaker so it was loud enough to piss off anyone within 4 rooms up, down and all around my room. The highest I ever tried was 6 on the volume knob...does anyone have anyclue what the problem could be? I'd really appreciate some input on this!