Cary SA500.1 mono blocks

I just added the 500.1 mono blocks for my front main and I have a hum on both. I tried lifting the ground pin on my PS AUDIO AC12 power cables with no change.I did try different power cables with no effect.The amp are on their own 20amp circuit plugged into a Richard grey 400 . Any help would be appreciated thanks.

Try unplugging the Richard Grey, and plug the amps directly into the wall sockets.

I'm done with them this sucks . I've done everything I can to silence the amps with no effect. I disconnected everything from all power in the room. I tried different circuits. Just the amp and speaker with no effect. I feel I did everything I could but my power situation sucks. I know the amp are fine it's just my power and all my other amps I've had are not this sensitive to bad power. I guess I will buy a new prepro or a Sony 4k projector.

If it's mechanical transformer hum you are hearing, try a DC blocker.

Do you have a cable TV connection in the room? If so try disconnecting it entirely and see if it goes away.

Hello sorry this is a old thread that I started and I should have put it in the amp thread to start with but I'm new and didn't know any better. I just wanted to give a update. I sent the amps back a few months ago because the hum I couldn't get rid of and I tried everything I could. Last week I talked the guy about some other amps that he sells and he told me that he just talked to Cary and they told him to check inside the amps for a loose cable connection. Well that was the problem and not a ground loop that I thought it was . So he told me to give them another try and alot better deal. So I did and they sound great and I'm keeping them. The guy was pretty cool he gave me deal I couldn't say no to.

Wow. That is awesome. I had a hum on a new product and it drove me crazy. Mine happened to be a ground loop but what a bugger. A brand new used product and I'm thinking I got the screw job. But everything finally worked out.