how do you get the hum out of hca 2205a parasound

i have a parasound 2205a amp that as soon as i plug the power cord in and turn on power it hum throughout all 5 speaker
Parasound amps are notorious for ground loops. Get a plug adapter that doesn't have a ground pug and try it. If that solves the problem, get a power cord made up with the ground pin not connected (or get one that has a removable ground pin like a PS Audio) Just make sure your preamp has a grounded connection and you'll be safe.
thank you very much will try it tonight