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What is DC offset on the AC power line?

I realize this question may be more appropriate in the miscellaneous section so please accept my apologies in advance. This may be somewhat amp related though, as in "don't use it with an amp".  

Can someone comment as to the pros/cons of a  DC offset suppression device, such as Emotiva CMX-2.

https://emotiva.com/products/accessories/cmx-2

I haven't seen this feature in other power strips and/or surge suppressors.

Thanks.


128x128gdhal
jea48
2,944 posts
 
"Just about every appliance in your home including that flat screen TV ... cable box all your computer devices and some of your audio equipment uses switching power supplies and cause this problems with the harmonics they create."


Add to that the micro processors in appliances.

//

"The  power your components draw from the grid  is loaded with these line harmonics that do the same thing in reducing transformer efficiency and you have the same issues ... reduced dynamics and head room

So even if you can evade the DC off set scenario some how ... you still have a big issue with the 3 phase users distorting the line and here is where a blocker like the Humbuster can be beneficia"


I would think anything ahead the primary winding of the utility transformer feeding the house/s, the secondary winding of the Power Company's transformer would not be affected. An isolation transformer will not pass DC.

Of course if your neighbor next door is fed from the same transformer it is possible something in their house could cause a problem in the other houses fed from the same transformer. It would/could depends on the appliance/equipment. In the majority of household appliances/equipment though I would think it would not be a problem to other houses fed from the same transformer. Now if your next door neighbor has something like an arc welder in his garage that could cause a problem.


exlibris
392 posts
 
This is fascinating stuff.  I came to this thread after reading about the  Burmester 948 Power Conditioner which is specifically designed to eliminate DC offset.   I live in an apartment building in a large city and I find that my system often sounds bad (anemic, glassy, cold, strained, two-dimensional, lack of power, no extension into the room) in the early evening (5pm to 8pm). 

I think davehrab may have hit the nail on the head with this:
" the real issue is the loss of efficiency your equipment experiences... 

The issue is that the loss of efficiency is not very audible like noisy RF can be ... your equipment just doesn't play with the authority or robustness it could or should"  




janewyman
59 posts
 
Hope this has not been mentioned earlier.  I had a hum in a Bryston 4ss2, called Bryston, they would get back, blah, blah, blah.  I went online and found a post where the OP suggested testing how tight the transformer was bolted to the chassis.  Not real tight, just good and snug.  I took the cover off the amp and used a wrech to see how tight the bolt was torqued for a reference.  It was not even finger tight, so I snugged the bolt down and the noise is gone.  Easy fix, no thanks to Bryston.
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