Projector and Audio noise in speakers
Looking for any hints or experience/ guidance before I head home from work to start tinkering. Have a dedicated HT close to being finished. Marantz 7704 -> Monolith 7X -> Klipsch THX in walls. Speakers have been installed and Audyssey calibrated...etc. Basically everything was running great. The Marantz and the Monolith are each on a separate dedicated circuit. They are connected with BlueJeans RCA's (like 6 ft).
Now last night we hang the screen and hook up a JVC DLA-X590R projector. Picture focus, zoom, shift all look awesome. First movie runs bring a tear to my eye. Finally my own HT.
However, now that the projector is plugged into the Marantz (HDMI through main out) I have a ground loop hum. Not terrible, but easily noticeable.
Marantz and JVC are on the same circuit. Both plugged into the same power filter. JVC is three prong. Marantz is two prong. The Monolith is two prong on a different 20A circuit and its own 20A power filter. Ive already tried grounding the amp to the power filter to no effect.
Obviously the issue is with the JVC being added in. I will move it to a different outlet circuit first. See if that fixes it. But all grounds lead back the panel box...so might be to no avail.
Will it make any difference to use a separate filter/protector for the projector? like plug them into the same outlet/circuit but on separate filters for the Marantz v JVC?
Can HDMI cables have issues onto themselves? can they be the culprit?
The Marantz has a ground terminal on the chassis. Worth a try. But how far should I take it, before saying it was of no help. To the panel? To the copper water main? I actually have a grounding terminal block at my panels that is to the stake outside...so yeah lots of options.
Least desirable would be to switch to XLR inter-connects.$$$ and time to order. Using RCA as I started with A Denon 3400H as the processor controller decided to upgrade due to great price of 7704.
any experience to share, or guidance is appreciated. thanks