Parasound HCA 2200 Hum problems

Hum thru both speaker and transformer mechanical hum when the power "loads up" i.e. the line voltage "dips". Mostly these units seem to have a buzz thru the speaker. Let me know if you have a problem and I can detail some easy mods for you.

Hello , my2200 does not hum, i was wondering if youve heard of turning the bias up on the 2200 i hear it sounds better,,,,, have you heard of this , and if so could you explain how to do this please.... any info would be greatly appreciated...... JC...

was interested to see this,thought mine was isolated problem my 2200 11 hums thru transformer,what can be done?

I have a Parasound 1206. I'm all for a lower noise floor. Any suggstions would be appreciated.

I have a Parasound HCA 1200 II that hums through the center and surround channels (not driven by the amp) unless I disable the ground.