So I work in a church and randomly today, during the sermon, I wasn't even touching the sound board (truthfully I was reading Stephen King under the counter) and all of a sudden the volume jumps and feeds back. I've been working there two years and this has never happened before. The only difference in the system today was that I was running a new double tape deck (gag, tapes) and had left the tape in knob turned up even though there was no feed running through from the tape. Now I would understand if the feedback sound jump was instantaneous, but the system had been acting perfectly normally for a good ten minutes. I run an Ev m2 board (craptastic) and akg wireless body mics. Any ideas for the reason for this random jump?