Look at the back of the receiver under a REALLY bright light for any wire strands shorting the speaker terminals. My first thought is that this sounds like a strand short...

If you are using the "A" outs try moving the speakers to B, turn on the "B" outs, turn off the "A" outs, then see what happens.

Try not to think about the batteries.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8