This is a tough one and his been driving me crazy for weeks now.
I have a ASRock Vision HT computer that I am using to run Plex. It is plugged into my Marantz via a single HDMI cable. The ASRock and the receiver are both plugged into a Monster Power conditioner.
When I turn the ASRock on I hear immediate audio feedback - electronic in nature over the speakers. As it boots up the audio changes and modulates, seemingly in line with drive access via the SSD.
Other things (Roku, Popcorn hour, etc.) plugged into this HDMI exhibit no noise issues, so I don't think it's a problem with the cable.
I can plug the ASRock into another HDMI input and I get the same thing, and in fact - even if I plug it into an input on the TV, i still hear the noise - even though it isn't directly connected as an audio source.
I sent in the ASRock computer thinking it was a problem with the mainboard, and they sent back a new one - but it has the same problem.
And, last but not least, I have an Intel NUC (next unit of computing) small system that I plugged in, and it also has the same problem.
HELP! I have run through all the troubleshooting steps I know of to eliminate the noise, to no avail.
Thanks in advance,