Because the toroid isn't manufactured properly; probably not wound properly. More than one example hums because whole batches probably made with sub-par QC. It's all down to the sub-contracted company that M. buys their transformers from these days. Evidently not the same QC, and probably not the same company, as in the old days. Once you stumble over a product that hums regardless of whatever else you do to remedy it, the only thing to do is get rid and move on to a different (and hopefully better) manufacturer. That's what I did. The monoblocks I own now (admittedly not massive) are absolutely silent.
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
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
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- 225 posts total
You must have nerves of steel, I would be a basket case. I would have thrown the amp in question through the stores window just out of spite. I would call McIntosh and ask if they could install the DC offset filter inside the amp for a nominal fee. If they balk, tell them you will be calling the states attorney general to file a complaint and also bad mouth them all over social media and in the different online forums. Anything to get their attention. Or, put it up for sale on Audiomart and move on. |
@twoleftears If that's the case McIntosh should pick up my bill and make it right for all the troubles I went thru. The salesman from the dealer I bought my amp from told me that they had specialty electrical companies come to the building every so often to make sure everything works properly, and said that they have the best in business when it comes to electrical wiring, installation, construction and whatnot, it is a specialty hifi store and I bet their electrical is top notch. This amp buzzed at three different houses all about 20+ miles apart, and I am still not sold on that it's only me and my electrical. But it is what it is and I have to live with it. |
tomiiv30 OP37 posts01-22-2019 10:25am As for correcting the connection of one of the dedicated branch circuit equipment grounding conductor that is now connected to the isolated ground rod, that’s an easy fix. More time will be spent removing the electrical panel cover and replacing it. Connecting the equipment grounding conductor, wire, to the ground bar will take about 1 minute. Removing the ground wire that goes outside to the ground rod 10 minutes, if that. IF the electrician roughed in steel boxes for the new dedicated wall outlets there is a very good chance they are not grounded. Good chance he just connected the equipment grounding conductor to the ground screw terminal on the IG duplex receptacle outlet. The mounting back strap is not electrically connected to the equipment ground contact on an IG receptacle. Unless the guy connected the equipment grounding conductor to the box, as NEC requires, the box and back strap of the receptacle is not grounded. That would have to be checked and corrected if need be. Time to look at both outlets? 15 minutes. If they need to be grounded? 5 minutes each, if that. Material? Four green grounding pigtails and two wire nuts. As for the electrician/contractor pulling a permit. I doubt you will find many electricians/contractors across the US that will pull an electrical permit for installing a couple of 20 amp branch circuits. If the customer says he wants the contractor to get an electrical permit then the contractor will do so. Note the word contractor..... Being a licensed electrician doesn’t mean he/she can pull an electrical permit. He/she is also required to have an electrical contractor license for the city he/she is working in to pull a permit. (In my area an electrical contractor doesn’t have to be a licensed electrician. He/she just has to have a licensed Master A electrician working in a management position. Even if the contractor is an electrician, but not a Master A electrician he/she is still required to employ a Master A electrician working in a management position. Burning question! Is your house wired with Romex? What did the electrician install for the branch circuit wiring? Jim . |
- 225 posts total