I have a B2 Combo and BA600-210. Running one from the Line 6 main out and the other from Line 6 Tuner/Aux out. Each sounds great alone, meaning, only one plugged into the Line 6 at a time. When both amps are plugged in and on, a bad buzz from all the speakers occurs. There's even a buzz if one of the amps is turned off, just as long as it's still connected to the Line 6. Any suggestions to eliminate the buzz?