try powering off the amp, then disconnect the inputs & power it back on. Check for the RFI; if not present then reconnect the interconnects but now with the Rx powered off.
Repeat the test, power the Rx back on. You could also try some different interconnects - finding these problems is a simple process of elimination.
Repeat the test, power the Rx back on. You could also try some different interconnects - finding these problems is a simple process of elimination.