Ground Loop?

I once had a ground loop thet crept up when I had my preamplifier on one circuit and my amplifier on the other. These circuits came from different phases in my main breaker box. When I got the amp and preamp on the same phase the issue went away. Don't know if that helps your situation, but I noticed you had two different feeds for components so it may be worth looking at that. Try plugging all components into the same outlet and see what happens.

One of my friends is a retired electrician and I'm going to get him to give the A/C line a go over. I also ordered a ground loop eliminator from Amazon a Btuty Buzz, if it doesn't work, I'll send it back.

I’d never had a problem with Ground Loop until my wife turned on an infrared space heater in the basement.  I had no idea what was happening and it drove me nuts until I figured it out.  What’s funny is we switched to a regular space heater and haven’t had any issues since.

I have had a similar issue. Finally resolved with isolation transformer. You may consider using a cheezy inexpensive audio xformer ($12 on Amazon) for troubleshooting before purchasing something like the iso-max that uses Jenson transformers.