I run a Art tube channel preamp and IPR3000DSP power amp. Last night during a soundcheck/rehearsal I plugged into to the snake for the house. I got a loud pop and silence from my speaker. The house was getting sound but my power amp was not. So I unhooked the xlr out and I got signal back to my power amp. So I used a 1/4" to XLR adapter from the sound man to use the Thru output from my IPR3000. Same thing, house is getting sound but my power amp is not. I run a balanced 1/4" from the Art preamp to the IPR. I vaguely recall having this problem once before. Any Ideas to what's going on. I think it has something to do with the balanced connections but not really sure what the problem is.