tom, we are here for you. Please keep posting but take it easy.
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
225 responses Add your response
tomiiv30"Moderators: What’s going on with you deleting my posts, in what way or form have I spammed or offended someone on this forum" That is what is so strange, odd, and unusual about the US you claim "First Amendmant Rights" but then when someone posts something accurate, truthful, and honest they're posts are deleted because some is offended, insulted, or hurt? It is time for the members here to state, declare, and demand that Free Speech be Permitted in This Group At All Times and I again salute your perseverance, bravery, and valor in bringing this matter to the attention, awareness, and consiousness of this group you are to be congratulated, thanked, and applauded rather than doubted, questioned, and challenged! Only a brave person such as yourself dare risk the onslaught of attacks, criticism, and vile characterizations you have suffered, endured, and tolerated all in the hope, expectation, and wish that others be shielded, protected, and defended against the sort of injustice, maltreatment, and abuse heaped upon you hear by those with alternative motives, goals, and designs! |
Did you ever try a power conditioner or DC blocker after not using the improperly grounded outlet? McIntosh should be more helpful. At the same time, it wouldn't make sense to put a DC blocker in all its products to make a small percentage happy. DC blockers are colored and roll off the highs. Why would audiophiles want a manufacturer to make their gear colored in an unintentioned way, when the customers with problems will benefit from cleaning up their power? The amplifier working at the dealer shows it's not broken. |
I have been in contact with Tom who has the problem. He is done with both his dealer and the manufacturer. No one is extending a hand to help. One of our esteemed Audiogon members badgered him so badly on McIntosh's forum @ AudioAficiando that Tom said he would rather set the amp on fire. as it was his money and his right. Well, the guy still wouldn't let it go, words were said and Tom got banned from the group. Had I been Tom, I would have lost my cool with this person way before that. Personally, I think Tom got screwed. I am the one who posted his problem at AF, so I have a strong opinion on this whole ordeal. That is all I will say about this. |
DC blockers are colored and roll off the highs.BS! atmasphere6,979 posts Repeat..... atmasphere said: We build them into all our amps. Bryston also does. Bet there are plenty of others too. . |
@ stereo5 As I said in an earlier post tomiiv30 needs to hire a Power Quality testing company to check the quality of the power in his home. Some electrical contractors may have the needed test equipment to preform the test, but most don’t. For many electrical contractors it is cheaper to hire a Power Quality company than buy the testing equipment. In my area a certified, qualified, power quality testing company charges about $125 an hour. A good single phase power quality analyzer can run around $10,000. And then you need a tech that is trained, certified, for its’ use. The tech will explain the problems, if any, and then recommend the solutions to solve the problem/s. If the power quality problem/s is coming in on the electrical service entrance conductors the tech will provide the necessary, certified, print out test results for the customer to give to the utility power company. Jim . |
jea48 tomiiv30 needs to hire a Power Quality testing company to check the quality of the power in his home.Agreed. And if the OP seeks a definitive assessment of the unit itself, he'll need to send it back to McIntosh or to an authorized service center for a complete evaluation. That's something his dealer - which he for some reason won't identify - apparently isn't equipped to conduct. Simply plugging it in to see if it buzzes isn't the equivalent of a proper bench test. |
Agreed. And furthermore: just because a unit doesn't hum (or whatever) in one location (be that the dealer's or elsewhere), it shouldn't hum in most domestic locations. Humming there is an indication of either an imperfect design or a faulty unit. Consumers should have a reasonable expectation of a unit working properly in their home, rather than manufacturers having an unreasonable expectation of utterly perfect electricity in every home. |
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cleeds1,989 posts02-08-2019 10:48am Agree. The AC mains voltage might be 115Vac - 117Vac at the wall outlet at the dealer’s store. The OP’s mains voltage might be 123Vac, maybe 124Vac. At the lower voltage the buzzing problem with the transformer may not show up. . I’m not a robot. . |
I'm surprised that Niagra didn't resolve it. Expensive piece. Sounds to me like "Mac" needs to get back to their roots.......perfect example of "bean-counters" making the final decisions that directly affect the output product's level of quality and/or performance. But, instead, let's regurgitate the response regarding the rolled-off highs! Never seizes to amaze me! |
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Guys I think it is pointless to argue any more on this matter, it is what it is, let’s just say I have bad electricity and as a consumer who paid top dollar to be in the wrong so let be it if that makes you happy, and McIntosh is the best audio company in the world. All I can say to whoever reads this thread and thinks of investing in this brand or this model in particular just make an educated decision of what you want to do. Too much disinformation is thrown on this thread that the more we argue the more inaccurate posts are being made which does not help anyone. This is going to be my last post on this thread..Peace Out!!! |
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I second the CMX-2. Solved my problem. https://forum.audiogon.com/discussions/jl-audio-fathom-f212v2-noise-and-hum |
miner42"You spend many $$$$ on the equipment yet you cry about spending $ to send to a service center when you probably have a service center near you that you could deliver to." I wonder if this OP ever submitted his amplifier for a proper, qualified, thorough bench testing by a factory authorized engineer or technician to establish beyond any doubt for certain whether the amplifier is in some way broken, faulty, or defective or if the source, origination, and cause of the problem is elsewhere. I applaud the OP's courage, bravery, and persistence in pursuing this problem and can only wonder what prevented him from seeking verified, documented, testable proof and validation of the issue here. |
@clearthink
Just to update you on your question if I ever did anything else with this amp and the answer is NO I did not because it is not worth my time, it is what it is I am using it as is and am trying to enjoy it while I have it. But it is for sale locally, once I sell it I will be moving to something else for my Home Theater and to a company with a better customer service and followers. I have been jumped and called names from so many Mac followers about this issue ain't even funny. As for the other Mac equipment that I have the MC462 and C52 those are keepers and love them both even though I had some hiccups with the MC462 having lose parts but it was replace with a new unit by the dealer and is all good now. Just upgraded my stereo speakers and got myself a new pair of Dynaudio Contour 60 and are in their break in period as I write this post. So far I am very pleased with them and will make a separate post about them. |
