I just bought a 788 and I was setting up my drum tracks. My configuration is: SD and BD, seperate tracks, though imp adapters into the normal inputs (AB) then my 2 overhead mics (Behringer ECM800s) into a blue tube mic preamp into the two aux inputs (LR) to channels 5+6. Anyways, the SD and BD came out fine, but for some reason, the overheads came out distorted. So I lowered levels, tried again, still distorted. It sounded as if I was overloading, but the levels on the blue tube and the 788 showed that the drums levels were only like 1/4 up. So I tried using -20db Pad, but to get a decent level, I have to turn it way up and I get a hum (no distortion, though). I can't figure out what's going. All my effects gains and stuff are at 0. The only thing I can think of is that I'm using a different power supply than what the Blue Tube came with, but it would seem that the -20db would have distortion too if that were the case. Thanks.