I have an Outlaw 950 preamp and have noticed a peculiar problem that I have not been able to correct. I have a passive subwoofer hooked up to an external crossover and amplifier. I have noticed a low frequency hum (on the subwoofer channel only ... other channels are clear) when I hook up the monitor video out (either S-video or composite) to my TV video input. If I leave the monitor out disconnected, no hum or audible problems. I tried reorienting all my power cables, equipment, removing the crossover from the audio chain, changing the interconnects, switching amps, etc. The hum sound only comes through the subwoofer channel when the video is connected to my TV video input. Something tells me it is a ground loop problem, but I have not been able to isolate it and I am open to any suggestions. I know the subwoofer, crossover, interconnects, and amps are good. Again, I get great sound from the 950 unit as long as none of the video inputs are connected from the 950 to my TV. I have other video preamps and have not had this problem, so I am baffled by this problem.