We can't put a man on the moon anymore. We can't get men into space without another country picking up hitchhikers. Sorry the problem could not be fixed. I have the 7125 and the 7500 and both are dead quiet. Since yours is quiet until you connect an HDMI cable I would steer away from the amp as the problem.

I don't know. I'm beginning to think the amp is the problem. Something has gone bad and the power supply isn't regulating or a cap blew and DC isn't decoupled properly or something.

I also don't buy that the transformer is acting as an antenna as ferrous core toroids make lousy antennas. However I'll grant that something might be broke here too.

My 7075 isn't dead quiet. I get a little of what sounds like transformer delamination noise which is strange becasue I thought the transformers where ferrite core not laminated steel. Haven't popped it open yet to explore. The noise level is low-I can't hear it from more than a couple feet away.

XenonMan and EEman -- I appreciate your thoughts that this is unlikely to be a mere transformer design issue, as I hastily speculated. I have decided to give this one last try and will exchange the 7900 instead of returning it. Also, I had an extremely helpful discussion today with ATI. cp1966 I'm sure you have already tried this, but the technician suggested gounding all components together to a common point and terminating w/a crimp connector or something similar. I have only done this with 3 of my four components, so it may work. Will report back in mid-January when I have received the new unit and completed my troubleshooting.

UPDATE;

Outlaw did accept the return of the 7005. I auditioned the new 8801 and it works great; NO BUZZ!