I just received a XS700 but when I hooked it to my cab and then into the preamp and played bass at a low volume when I went to move the power amp an inch to fit better on the cab. all *beep* broke loose, there was a terrible crackling and fuzz sound even as I turned the amp off. I had to unplug it to kill the noise. After checking all the connections I turn the amp back on and it started again. Now I am afraid to try it again but I'm stumped. Any Help? Please?