Buzzing just won't quit: Can someone please help?


Hello,
First let me thank you for taking the time to read my post. I’ve been trying to get this buzz out of my system that I just can’t lick. It’s really starting to drive me nuts. Here is a spectragraphic image of the sound https://imgur.com/a/xREqG. Here’s a WAV of the sound: https://drive.google.com/open?id=0B_YygM_VDhV9RWlPMEVudjBnb28 

My system:
Bryston BP17 preamp
2x Schiit Vidar poweramps, running in monoblock
Sonus Faber Venere 3.0 speakers.
Velodyne DPS10 sub
Schiit Gungnir MB DAC
Music Hall MMF 2.3 TT
Marantz NR-1604 AVR, w/ Roku, CC, and Blu-ray
Samsung Plasma TV
No cable

Facts:
- All devices are on the same circuit.
- The buzzing comes through on LR channels (powered by Vidars) and powered subwoofer, BUT NOT through the surround sound speakers, which are powered by the AVR.
- Poweramps, preamp, AVR, and TV are all on the same plug (via ATC power conditioning strip)

What I’ve tried:
-I have physically disconnected EVERYTHING except the poweramps and the speakers. Everything was unplugged and disconnected EXCEPT the poweramps to the speakers (Wall > Vidar amp (no input) > Venere speaker). Subwoofer unplugged/disconnected. This made no difference.
- I’ve tried an Ebtech HumX hum eliminators on the amps. Did nothing (though it did wonders for my plasma TV).
- I’ve tried switching around to different wall outlets (though all are on the same circuit).

What I’ve determined so far:
- The problem ISN’T the Schiit poweramps. I know this because I hear the buzz coming through the sub, which has its own power.
- The problem isn’t due to the 10000 devices I have because it occurs even when the entire system is disconnected except amps and speakers (with no input in the amp).

So what can I do? Is there some kind of fancy "power conditioner" thing I can buy? One of those Blue Circle Thingees? If I buy a power conditioner, does it have to have regeneration? Would something like a Panamax M5300-PM or something like that be adequate?

Please help me!
naseltzer
To diagnose the problem, unplug and disconnect everything and re-connect one thing at a time.
1. connect only one Schiit Vidar to a speaker, and plug in the power cord and turn it on, if no noise then go to the next step.
2. connect the other Schiit Vidar to a speaker, plug in the power cord and turn on both Vidar, if no noise then go to the next step.
3. Power off both Vidar, connect the Bryston BP17 preamp to one of the Schiit Vidar via XLR cable, power up the preamp and both Vidar, if no noise then go to the next step.
4. connect the other Schiit Vidar to the preamp and power up the preamp and both Vidar again, if no noise then go to the next step.
5. plug in the subwoofer, power up the subwoofer, preamp and both Vidar, if no noise then go to the next step.
6. connect the left channel line in of the subwoofer to the preamp line out, power up the subwoofer, preamp and both Vidar again, if no noise then go to the next step.
7. connect the right channel line in of the subwoofer to the preamp line out, power up the subwoofer, preamp and both Vidar again, if no noise then go to the next step.
8. plug in the DAC, power up the system, if no noise then go to the next step.
9. connect the DAC to the preamp line in, power up the system, if no noise then go to the next step.
10. play some music if no buzzing noise then you can connect the AVR, TV....
Hope you can find the culprit, good luck!  
One more thing is a ground lift they sell ground lift adapters for xlr,  and rca 
for there  is a differential problem where one component may be wired a certain way  another grounding scheme may not be so good  if you have a ground lift 
try on each interconnect cable until it eliminates it guitar center sells things like that or can order them..i spent a week one time going through this ,also your electrician if good can set up a true ground outside 4 ft Copper pipe 
and for sure Dedicated lines only , 12awg Or 10 awg Copper only no Aluminum,and high quality Copper gold outlets  not the junk they wire houses with are garbage .a Pangea Copper around $50 , or other brand,
a clear step up .yes it absolutely will add to your fidelity .
you may spend $ 500 to get dedicated lines, and the best grounding ,and outlets 
these are a must to get the most out of your system.any times other things in the house feed off and transmit noise frig,washer,dryer . Dedicated line, to dedicated 
ground .also A home surge suppressor to circuit breaker 50-80,000 Leviton for around $200 helps safe guard your home .10x better then any power strip.
If you’re in the U.S., it’s against code to install a second separate grounding rod. Also, having a second grounding rod can cause a voltage differential to develop between the two grounds, actually causing a current to flow on the ground wire.. all connections need to be clean, tight and tied into the same ground as the rest of the system.  

I agree on the panel based surge suppressor being a good idea. But they are designed to work with a service entrance suppressor and an outlet suppressor you use at the appliance. Surge suppression is supposed to happen in stages, with each stage taking more of the current out of the surge.

Sorry, not trying to be argumentative. I just did a lot of research into this when I was deciding on what to do. I'm certainly no expert, but those were at least two things I learned in all my reading! 
toddverrone
If you’re in the U.S., it’s against code to install a second separate grounding rod. Also, having a second grounding rod can cause a voltage differential to develop between the two grounds, actually causing a current to flow on the ground wire.. all connections need to be clean, tight and tied into the same ground as the rest of the system.
+1 about the grounding, and +1 about all connections being clean and tight. That applies to every connection in the service panel, including the breakers themselves, and the connections between your meter pan and the panel.
(Wall > Vidar amp (no input) > Venere speaker). Subwoofer unplugged/disconnected. This made no difference. 

Well then it has to be the amps - if I read your above statement correct. that is is also present in your subwoofer is a separate issue.  

Best off luck 

Peter