Hi Bob,

These are 2 possible options for you to try.
1. Go and buy a cheap DD/DTS receiver and try it. If the buzz isn't audible then the problem is the Parasound. Then take back the Receiver (Not the most honest option out there, but it is doable)

2. If you have a local dealer by you that is authorized to repair Parasound, see if they will loan you a pre/pro or receiver to test the buzz with the premise that if it fixes the buzz then you will a)buy an upgrade from them or b)have them fix the Parasound.

Personally I think option 2 is your best bet as most dealers are willing to work with customers....Tony