I'm using this amp for my DJ set up at home - I'm using x2 CD Pioneer 1000's and a Pioneer Mixer. I put the mixer into the CD output section in the back. I've set up the amp to CD mode, and adjusted the digital input to Analogue. The speakers are making a loud humming sound - I can't figure out why. Is it because the cables for the surround sound are set up wrong? Any help would be much appreciated - I'm against a brick wall and no clue what to do next....