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
This guy has a warrantee he should just return the component to the manufacturer for repair and while it is there hire a trained, competent, licensed electrician to correct the improper, faulty, and dangerous connections previously constructed by the prior contractor also he should name hear the dealer that sold him this component why hasn't he already mentioned that?
All the emphasis is on McIntosh's famous output transformers.  Little mention of the IE power transformer.  Search Audiogon for McIntosh + hum.  There are threads going back years.
No need to name names for the dealer, they have done so much actually they have done as much as they knew because they have not been trained by McIntosh to deal with this kind of situations. They did not know about this problem until I brought it up to them, and even them can’t get any clear answers back from McIntosh as to how this should be dealt with. All McIntosh did was to tell me and my dealer that I have DC on my mains and how they know if I have Dc offset I have no idea they never came to my house to check, and that was that no more interactions. It looks like I am on my own.
They replaced two units so far one being the one discussed in this thread and another one that had loose parts.

If you did not read my previous posts, this unit that buzzes like crazy at my house and at two different houses, did not buzz at the dealer at all and it was dead quite - How is that possible I have no idea and I think that even if I return this unit back to the manufacturer they would say the same thing that this unit works properly.
Also the warranty time that it would take to send and receive the unit back it would be about a year or maybe 6 moths the least.


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And round and round we go. It's this, it's that, believe me. You made a simple case for me anyway. You took the unit to 3 different houses miles apart from each other with the same humming result. What more has to said? Defective unit, no?