What is DC offset on the AC power line?

Did you read the DIY Audio thread I provided?

http://www.diyaudio.com/forums/solid-state/2080-dc-filter.html

As for the Web Link you provided, my computer says it is corrupted and advises not to open it. I suggest you provide another link for the product.

Here are a couple of Links for you to read on the subject.

You can not measure for DC on the AC mains with a regular multi meter.

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

http://www.diyaudio.com/forums/solid-state/2080-dc-filter.html

//

Quote from Nelson Pass:

"If you are experiencing mechanical hum from your
transformer, it is often caused by the presence of
DC on the line. Usually this comes from some appliance
using current asymmetrically, such as a lamp dimmer."

"The hum comes usually from toroidal transformers, which
saturate easily with DC, and when they recover, they
draw an extra pulse of current, causing the noise."

gdhal,

Lots of stuff inside there. I do not have any experience with the Emotiva device.

Are you experiencing a loud mechanical buzzing/humming sound coming from a torrid transformer in a piece of your audio equipment?

There is a member here on Agon that used to build DC blockers. I might be able to find his username if you need a blocker.

Edit:

Gbart is the Agon member's username. If interested you might try sending him a PM over the Agon message system.

"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.