So, I'm jamming with my band....using my friends rig, so I kinda feel bad about this....and all of a sudden, the sound just cuts out. I was using 4x10 cab and it just died. No sound at all. I switch basses, check my batteries and cables and nothing. Then I decided to switch cabinets and full sound. So, I know it's not the basses or the head. Any idea what the problem might be that would make all 4 speakers just die like that? Thanks for your help.