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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
toddverrone's avatar
toddverrone
840 posts
 
Do you have a different amp you could drop in the system and narrow the problem to the Schiit amps? Also, I know you said you disconnected EVERYTHING, but I just want to be thorough: the amps make the noise even without ANY input cables physically connected to the amps (other than AC), correct?
Have you tried lifting the ground on the amps (using a cheater plug), only as a diagnostic measure?
naseltzer OP
7 posts
 
Hi all,
Thank you so much for the responses. 
Zephr, I've tried unplugging everything else on the circuit. The buzzing still occurs with both the amp/speakers and the powered sub (independently). I've tried plugging the amps and the sub directly into the wall. No line inputs. 

James, noise never has and still doesn't come out of my AVR, which is what I used before I got the amps. I never noticed the buzz coming out of the sub until recently, however, because it's quieter and not noticeable from my listening position. Speakers buzzing since I got the amps. However, I had an Emotiva A-300 amp for a while and I don't recall it buzzing. It didn't have a ground and wasn't as powerful. It might have buzzed but just more softly. I can't be sure.

Raindance, my interconnects are Blue Jeans XLR between pre and amps, Blue Jeans RCA between DAC and pre. Cheap RCAs to sub. However, this noise still occurs with amps and subs simply powered on with no inputs.The noise loudness seems to fluctuate, generally a bit louder when I first power things on. Could be up to 46db, but will chill out down to maybe 36db.

Todd, I don't presently have a different amp, except for the ones built into my AVR and my powered sub. I suppose I also have one in my headphone amp. There is no noise in speakers powered by the AVR or headphones powered by the headphone amp, but the noise is present in the sub. Oh, I did previously have a cheaper Emotiva amp and I don't think it made the noise. That being said, it wasn't as powerful and I don't think it had a ground. I just tried lifting the ground on one of the amps with a cheater plug. No change. And yes, that's correct: makes noise with ONLY amps plugged into wall, speaker cables to speakers with no inputs, with no sub. Same for sub with no speakers.
auxinput
2,920 posts
 

Uhm, unplug everything, then connect your speakers to the AVR to see if the AVR has the same problem. 

I'm wondering if it could be a switching power supply somewhere on this same circuit (or something like florescent/led lighting on the same circuit).  It is possible that it could be house wiring.  You could switch off the master circuit breaker on the panel and go from outlet to outlet to make sure there is a good tight clamp-down on the bare wires.

toddverrone's avatar
toddverrone
840 posts
 
Can you try using RCAs from pre to amps? Or are they balanced only? Though that shouldn't matter, since you said it happens with the amps having no cables going into them.. 


elevick
2,636 posts
 
Since you hear this through your sub too, I would try this:  Take either the sub or your power amps and speakers to the other end of the house.  Or, you can run a really long extension cord.
This will tell you if it's the whole house or just that breaker.  If it's your house you would take a different route than if it's just one circuit.
The Nordost is way better than the thingee (way more expensive too) but neither can clean up a totally bad electrical feed.
No more advice from me until I know more about the rest of the home.

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