If you ever have amp transformer noise related to DC

[elwaylite]

Try the Emotiva CMX2.

I was pulling my hair out and finally narrowed my issue down to the plasma causing the noise, and it appearing to be DC issues on the AC line.

Hum
https://www.dropbox.com/s/shevqhnhz049zom/Hum.m4a?dl=0

No Hum
https://www.dropbox.com/s/bgvzb0v69uig4pg/No Hum.m4a?dl=0

 

[highfigh]

DC, from where? Hum is AC- it has a frequency, DC doesn't. If the TV or subwoofer is on one circuit and the rest of the system is on another, you have a ground loop. This can happen if they're across the room, too. Resistance on the power wiring is usually the cause. Open the forum, go to the top and look for a thread about ground loops and hum.

That white wire- what is it and how far does it run parallel to power cords?

 

[elwaylite]

It's DC offset, and it causes a mechanical transformer noise in toroidal's. I did the testing, I also used a multimeter. The plasma is the cause(plasma off, no noise no line DC issue), and the emotiva fixed it (designed to combat this particular issue). It is no ground loop hum, maybe buzz in a wave would be a better description. Regardless, there is a reason a cheater plug did nothing, as well as two quality line conditioners. It was DC offset.

I linked the before and after sounds so people could hear what I heard.

 

[elwaylite]

"Most of the time, the DC offset is transient - it appears for a short while, then goes away again. When it is there, toroidal transformers may complain loudly, by making growling or buzzing noises. It is important to understand just how this happens, and what can be done about it if it causes problems."


http://sound.westhost.com/articles/xfmr-dc.htm

 

[BoredSysAdmin]

nice, but this unit would probably do the same, alas without Audio/Video pedigree
http://www.newegg.com/Product/Product.aspx?Item=9SIA2F81P59134&cm_re=APC_LE600-_-12-106-065-_-Product

 

[elwaylite]

Not sure, I spoke with Outlaw some too and the other recommendation was an isolation transformer. I'm just glad I got it fixed, a problem like that is not good and annoying. You know its bad when the wife asks about it.