Dear audioholics forum - I have a Denon x3700H that I am looking to get working with an Outlaw 500x amp. Ideally I'd like to power the Front, Center, and Surrounds with the Outlaw and let the Denon handle the sub and 4 height channels. It would be a 5.1.4 (single powered sub - hopefully will be able to add a 2nd sub in the future). \n\nHere's my problem - no matter what interconnect cables I use when the amp is connected - all I hear is a pretty loud (I think 120Hhz?) hum from the channels powered by the amp. Audio sounds muted too. I can't find a way to specifically enable\/disable the internal amps in the Denon (I've dug throuth the manual several times). I called Denon tech support and after a long wait they indicated all I needed to do was simply connect the amp to the pre-outs and that was it (in other words the Denon is smart enough to detect the amp I guess).\n\nOnce I disconnect the Outlaw and let the Denon run the 5.1.4 setup - all sounds fantastic - absolutely no hum\/issues whatsoever. Reconnect the amp - hum and terrible audio. I did try the following to no avail:\n\n- different interconnect\/RCA (good quality cables used - short 1.5ft lengths)\n- different A\/C cable for the Outlaw\n- tried plugging the Outlaw into a different A\/C circuit in the house\n\nThe closet where the A\/V equipment is in has its own dedicated 20A circuit. The home wiring is all to code\/new <5 years old).\n\nI'd be beyond thankful and appreciative if someone could point me in the right direction or might have experience with this configuration.\n\nThanks!\nTony C.