The purpose of these forums for me is to learn and swap opinions. You and others do share the same opinion on my External Amp question and I will use this to further my audio quest in other directions other than amps . Maybe put in towards new speakers or some room treatments.\n\nAs for my Crown issue it will produce the feedback with no power cord plugged in and a ground between AVR and the Crown Chassis. I have 3ft shielded rca's and the moment I plug them in to the crown I can hear the feedback . My speakers are not connected to the crown they are connected to my AVR but the crown will still produce feedback in all six speakers once its connected to my AVR via the pre-outs.\n\nOut of curiosity when using your crowns as sub amps how do you get phase control? Is their a product they sell to do this?I don't see how it could be feedback.