Thanks guys!
I think I'm going to try out the PS Audio Humbuster or UPC-200HB.
The transformers seem to be humming, so I'm guessing there is DC in the line. Also, the hum appears shift in severity, from none, to low, to high depending on the time I turn the amp on.
Otherwise, the difference in sound quality is marked, even at low volumes. I'm hearing subtle detail I quite honestly never heard before (in my limited listening so far), two examples:
Nine Inch Nails - The Downward Spiral (SACD)
The very beginning with the concussive "heartbeats", with the 7200 I can hear a layer of soft piano taps and a "record dust" effect I never heard before.
Lost Highway - Soundtrack (CD)
During the opening of Angelo Badalamenti's
Red Bats with Teeth there's a strange rocking chair crackling effect and a really eerie synth sound effect I simply never heard before. Also Lou Reed's cover of
This Magic Moment sounds simply fantastic now. I know this might sound weird, but it now sounds the way I always imagined it should sound in my head.
I've only sampled one DVD:
Terminator 2: Judgment Day.
The first thing I noticed was all the "new" foley sound effects I heard, like the rustling of Arnie's leather jacket or the sheer "realism" of the sound of his boots hitting the tile floor of the Cyberdyne building after kneecaps the SWAT team.
And everything simply sounds better as well, even dialogue from the center channel. One small detail that sounded awesome was the Terminator grabbing a pry bar to rip his shattered arm from the large gear the T-1000 pushed him into. The "dragging" sound of the bar was eye poppingly realistic in a way I never heard before. As you can tell, I've seen T2 way too much. :p
The film sounds so much better to me now, I gotta question the real need for "lossless" audio tracks if "standard" Dolby 5.1 can sound this good.
If I can temper or kill the hum beast outright, this thing is a keeper!