Guys, I just upgraded from a Firebox to an Apogee Duet. I'm using a Macbook Pro and Rockit RP5G2 monitors... So with the Firebox I had a fairly present hum hooked up, not playing anything, just idling. With the Duet the hum dissipated and is now almost silent. The only thing is static will come through generally when I do something processor intensive (or with power adaptor disconnected a light squeal), and while still fairly quiet, the fact that it comes and goes is driving me bonkers enough that I am turning the monitors off while not listening to music or recording. I purchased a Belkin PF30L, a fairly hefty 10 outlet 2 stage power conditioner, and while things may be a bit quieter it seems the pattern remains. I'm bummed. Any suggestions? I've played a bit with the position of my wiring but it doesn't seem to help much. One thing too is the Duet is a used unit that's a few months old. It has a bit of patina on the big knob that indicate it probably was thrown in a gig bag and jostled around a bit. Could it possibly be damaged, or is this typical due to having unbalanced outs? Note that it's completely silent on the headphone out.