chess, I have seen other reports on the Parasound "Hum" to. Perhaps I have just gotten lucky or something. I can't explain it at all. To me at least Parasound builds nice stuff. I have never had a problem with any of Parasound's products. Not only have I had there amps but for a time when I went completely off the wall I was running the AVC-2500U for a pre. Great pre but when my wife found out what I had into it................I had to sell it. lol