Sorry M. Zillch, and I really am not trying to a smart Alec;
#1- I do NOT have cable, I have a DirecTv Sat service, and EVERY isolation transformer I have seen linked or seen is specifically for cable systems, they clearly state they will not work with Sats......If I missed something in that link to Amazon for the Viewsonic Isolator that does say it works with a Sat, I am sorry, but I thought it said it is for cable ONLY.
#2- Check to see if the buzz disappears when the cable/sat RF coax wire is disconnected from ALL devices in your system [TV, cable/sat box].
If I had not posted the result, it did not disappear, the cables were disconnected and the DVR was unplugged and the buzz was still present.
I did miss this response,
"It would be nice to think that everything connected to the same circuit breaker has "the same ground potential", however that's not always the case. Even two outlets in the same room may have a variation large enough to cause problems in some sensitive gear, and the Marantz is known to be a sensitive device. Try piggybacking all your various AC strips to each other and then the SAME outlet. If distant devices won't reach (sub? TV?) then don't even connect them to any AC outlet and see if the buzz is gone.
I can try this with the new unit and see if it sounds ok.
#3- I dont have cable, I have Sat system.
#4- I dont have cable,
#5- I dont have cable
I just received the new unit Friday and I will spend some time this weekend hooking it up. I am going to try connecting the Marantz to the amp via RCA unbalanced wires instead of the XLR cables.
Again, I sincerely thank you for the time spent offering suggestions. I have probably spent 5-7 hours at a minumum on this, probably more like 10-12 (time flies when your focused on something)