DC Offset Blocker/Killer - where to buy in the USA


   I have McIntosh MC8207, the first unit I bought from an authorized dealer came with a loud buzzing coming from the left transformer, and was replaced with a new unit which came with even a louder buzzing. The buzzing can be heard from 8 feet away. Then I was told to have install new 20 amp outlet that has its own isolated grounding.
   That was done professionally by an electrician who installed two isolated 20 amp outlets, two 20 amp circuit breakers, two copper polls for grounding for each outlet, each outlet has its own neutral and power line. After all this done the buzzing sound was still there.
   I was then told to buy a power conditioner which I did (Audio Quest Niagara) which was like $4000 and that did not help. Called back McIntosh and was told that I might have DC offset in my AC line and was told by McIntosh that I would need a DC Offset Blocker/Killer to which when I asked them where to buy one they told me to go on the internet and search to find one, to which I cannot find one.
  This bothers me a little bit, if you as a company think that I have dc in my ac and i need a dc blocker wouldn't you need to sell one as well. I brought this amp to my friends house and it was the same no improvement, so my guess is that he has dc in the ac line as well.
   So If anyone of you knows where to buy a DC Offset Blocker/killer please let me know, but even if this helps kill the buzzing wouldn't you guys think that this expensive somewhat hifi amp/brand should be silent from the factory. I mean this is two units in a row all purchased brand new.

My house is 5 years old, everything is brand new, the whole neighborhood is about 8-9 years old, my electrician says that I have perfect power coming to the house and everything looks fine.

Thank You

tomiiv30
@cleeds

I don’t need anymore help nor do I care about this brand anymore. You think that $5-6000 would do me any harm, no. but the reputation of once good company can be ruined by cases like this. I think they have more to lose than me. I am done with them anyway and would not spend a cent more on it.
And I was at piece until you dragged me back into it, and I am really trying to understand you why do you want to know about this dealer so much, they have done their job what else can they possibly do.

And the MC8007 is not the only amp I bought I bought the MC462 and C52 and a Marantz AV8805 from the same dealer, so as you can see I spent pretty penny buying McIntosh equipment, and I was planning to buy another MC8207, a pair of Sonus Faber speakers but guess what, that ain’t happening no more. And once I sell my McIntosh equipment that is only 2 moths old since bought brand new I will move on to another brand.
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tom, can you remind me if the amp buzzes when the tv cable box is not attached to your preamp?  I had a buzzing that only occurred when I hooked my stereo up to have the tv audio play over my stereo.  As soon as I detached the cable box from my stereo the buzz went away.
@jetter 

nothing is hooked up to the amp, only the power cord that is plugged into the outlet, no speakers, no premps or av receivers.
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