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.
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.
If the claim that the amplifier was defective was valid, authentic, and genuine then why wouldn’t this person who came hear only to complain return the unit to McIntosh for repair, adjustment, or replacement and why wouldn’t he name the dealer who sold him this defective, damaged, or inferior unit?
The unit IS NOT defective, When the OP took the amp to the dealer it was taken to the service department. There it was plugged in, turned on, and the torid transformer did not buzz/vibrate. The OP said the torid transformer was quiet. The OP was in the room during the test. Again, the torid DID NOT buzz/vibrate. It was quiet.
So what good would it do to send the amp back to the factory? The amp is not defective. It works as it was built to function. If the consumer has DC offset on his AC mains the torid transformer will buzz/vibrate. The more DC on the mains the louder the buzz.
Should the manufacturer have incorporated a DC blocker on the line side of the torid transformer? Yes. But the manufacturer chose to save a few bucks. Ron, a McIntosh representative, said they get maybe 5 complaints a year about mechanically buzzing torids. His advice to fix the CUSTOMER’S PROBLEM is to buy a DC blocker.
Probably most manufactures that use fairly large torid transformers, in their equipment, install a DC blocker. McIntosh does not.
//
Repeat!
When the OP took the amp to the dealer it was taken to the SERVICE DEPARTMENT. There it was plugged in, turned on, and the torid transformer did not buzz/vibrate. The OP said the torid transformer was quiet. The OP was in the room during the test. Again, the torid DID NOT buzz/vibrate. It was quiet.
//
Repeat!
Should the manufacturer have incorporated a DC blocker on the line side of the torid transformer? Yes. But the manufacturer chose to save a few bucks. Ron, a McIntosh representative, said they get maybe 5 complaints a year about mechanically buzzing torids. His advice to fix the CUSTOMER’S PROBLEM is to buy a DC blocker.
FROM THE BABES MOUTH. Ron, a McIntosh representative, said they get maybe 5 complaints a year about mechanically buzzing torids. His advice to fix the CUSTOMER’S PROBLEM, again, CUSTOMER’S PROBLEM, is to buy a DC blocker.
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 have many pieces of McIntosh equipment that have been fault-free for years.
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!!!
The improper grounding outlet has nothing to do with the Niagara, the Niagara was plugged in different outlets that have nothing to do with the outlet that was improperly added.
The top schematic DC blocker is one used in piece of Bryston equipment. I’m guesting a power amp. The schematic below the one for the Bryston is one used in a Crown amp. Again no chokes.
Now some stand alone DC blockers sold do have filtering too. But purely DC blockers without filtering can also be bought. Chokes are not needed.
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!
Simply plugging it in to see if it buzzes isn’t the equivalent of a proper bench test.
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.
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.
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.
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.
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.
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.
Instead of sending to McIntosh, send to another authorized service location that does not have a vested interest - Like Audio Classics. Their service is top rated.
Moderators: What’s going on with you deleting my posts, in what way or form have I spammed or offended someone on this forum. No wonder people like me never get help, because you let people insult me and lie about me but you would delete my posts when I defend my self. I was accused of deleting my own posts by @cleeds which is a big fat lie because I never deleted it any of my posts. I was accused that I am lying about my problem which is not true again and you have done nothing about it.
There is no point of me posting here anymore because with moderators like this I am not getting anywhere.
Just so you know I have copies of everything that has been posted on my thread so you can delete as much as you want.
tomiiv30"And since McIntosh has no smart answer they chose to stay quite as you can see." I 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!
Of course I am being truthful, If I was not McIntosh and the dealer would’ve been on my ass from the get go. They know who I am, I have spoke on the phone with Chuck twice and my dealer spoke to Ron on the phone few times but I was never given a clear answer as to why is this happening and if they are planning to do something to fix this problem.
Both me and the dealer were told by these two McIntosh representatives that I need a DC blocker and that I have bad electricity of dc offset on the mains even though McIntosh never sent no one to my house to check if I really have dc offset on my mains, they are just speculating, and even if I do have dc offset aren’t they suppose to help the consumer to come up with a solution, because I am not the only one with this kind of a problem. And since McIntosh has no smart answer they chose to stay quite as you can see.
FWIW, my reading of the thread leaves me with essentially zero doubt that the OP is being entirely truthful. And I agree with him that it is very likely that investing the time, physical effort, and money that would be involved in sending the amp to McIntosh would result in a finding that it is functioning as designed.
Ron, a McIntosh representative, said they get maybe 5 complaints a year about mechanical buzzing torids. His advice to fix the CUSTOMER’S PROBLEM is to buy a DC blocker.
You’re just repeating a claim made by an anonymous poster on Audiogon. We really don’t know if it’s true, or not.
Your are the one that seems to be having a problem believing the OP. Here’s a novel idea, why don’t you call McIntosh and ask them for yourself? That way you will get the information first hand. Post back what they tell you.
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.
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.
Are you out of your mind ... you are something else bud. People
like you make the brand look even worse than what it is right now ... Why don't McIntosh come to my house and check out the problem, I have
hiatal hernia and been diagnosed to not lift any heavy weights ... I still cannot understand how is it my responsibility to do
all this things is beyond me ... I am left alone with nobody
backing me up. I get back home all pissed off ... if some of you smart asses would like to prove me
wrong than go ahead come to my house check out the amp and go from
there.
I'm much more sympathetic to your plight than you understand.
I hope you're able to get whatever help you need.
Ron, a McIntosh representative, said they get maybe 5 complaints a year about mechanical buzzing torids. His advice to fix the CUSTOMER’S PROBLEM is to buy a DC blocker.
You’re just repeating a claim made by an anonymous poster on Audiogon. We really don’t know if it’s true, or not.
Why do you have a problem with understanding McIntosh’s response to the customer?
I’m not the one with the problem here. I’m happy with my system and - for that matter - I’ve always been happy with McIntosh service.
So why do you continue to insist the OP send the amp to McIntosh?
I’m not insisting on anything. But if the OP wants his amplifier evaluated, that would be a good first step.
I don’t care where he bought his amp. That the OP won’t name the dealer just suggests that there’s more to this issue than he’s willing to acknowledge
If there was something else that I am not acknowledging McIntosh would’ve been all over me. Are you out of your mind. This is a brand new amp bought from an authorized dealer, you are something else bud. People like you make the brand look even worse than what it is right now. Why should I send this heavy ass amp to anyone for evaluation is beyond me. Why don’t McIntosh come to my house and check out the problem, I have hiatal hernia and been diagnosed to not lift any heavy weights but I did lift this heavy amp to take it to the dealer, not once not twice but three time and spent at least hour and a half driving one way to go to the store. I still cannot understand how is it my responsibility to do all this things is beyond me.
Here is the story:
I go out to this authorized McIntosh dealer who is about an hour and a half away from, buy this brand new amp, bring it home find out there is a buzz call dealer, dealer says bring it back we will order you a new one new amp is ordered, I go to pick it up bring it home plug it in and boom louder buzz than the first one. Call dealer back, dealer says bring it back to the store for testing, I bring it to the store to the techs department plug it in and amp is dead quite and bam I got no case, dealer says see it works and there is no buzz, dealer calls McIntosh to tell them that amp is dead quite at their store and McIntosh says that there is nothing else that can be done, bam I am left alone with nobody backing me up. Actually I am told that I need a DC BLOCKER and was told this by Ron and Chuck but they won't even tell me where to buy one which made the situation even worse. ALL I WAS TOLD BY CHUCK IS TO GO ON THE INTERNET AND SEARCH FOR ONE - IF THIS IS CUSTOMER SERVICE AT ITS FINEST THAN I DON'T KNOW WHAT IT WOULD BE IF OPPOSITE OF FINEST.
There is nothing I hide it’s all here in the open and if some of you smart asses would like to prove me wrong than go ahead come to my house check out the amp and go from there.
Ron, a McIntosh representative, said they get maybe 5 complaints a year
about mechanical buzzing torids. His advice to fix the CUSTOMER’S
PROBLEM is to buy a DC blocker.
Repeat.
His advice to fix the CUSTOMER’S
PROBLEM is to buy a DC blocker.
Why do you have a problem with understanding McIntosh's response to the customer? McIntosh knows the torid transformer buzzes if there is DC offset on the AC mains. So why do you continue to insist the OP send the amp to McIntosh?
You want to know so bad where the OP bought the amp why don’t you call the two dealers tomorrow ...
I don't care where he bought his amp. That the OP won't name the dealer just suggests that there's more to this issue than he's willing to acknowledge. In any event, it's all a moot point now that he says this:
I have made up my mind about this brand not just this amplifier ... The amp buzz has
nothing to do with what I have done ... the experience I’ve had so far
with this brand alone is unforgettable and was unpleasant. After
spending so much money and not even one phone call was made back to me
that should tell you something ...
He seems to want someone to rescue him from his misery, but he won't send the amplifier in for an evaluation. That just seems odd to me. If he doesn't trust the factory, there are many independent, authorized McIntosh service centers - perhaps even one within driving distance for him. But he has made up his mind, so there's really nothing else to talk about here.
I have PM'ed him but never got a reply back, maybe he hasn't seen the msg yet or he is just not making them anymore.
Also there are more than 2 McIntosh dealers in or out the Chicago area but again I am not going to name the dealer it is not needed since they have not done me crazy wrong. I did not buy from those two you mentioned I can tell that much.
@stereo5
The way they have acted so far I don't know if I can keep my anger inside me without expressing my self out loud. I know they frequent this forum and other forums and if they wanted to help they would've done by now but none of them have replied to this thread or any other that I have made. I can sense they have their own fanboys that want to throw the ball at me like if it was my fault or something.
I would call McIntosh and talk to one of the higher ups and get some action. No one is going to call you if you don’t keep on their ass. You have a brand new amp collecting dust in the corner, not doing anything isn’t the answer. I would call and ask to speak to the persons supervisor, then when the supervisor comes on, I would ask for their supervisor. Once you are at the top, express your concerns and disappointment without getting angery (at first). See what happens. As a last resort, you could tell them you are going to plaster your story all over social media, the online forums, the works. Trust me, they will change their tune fast.
@ cleeds You want to know so bad where the OP bought the amp why don’t you call the two dealers tomorrow and find out which one of the two sold the piece of cramp McIntosh MC8207 to Bill, the OP.
As for sending the amp back to McIntosh what part of it would be a waste of time don’t you understand?
The thing weighs 100lbs. What do you think it will cost to send that boat anchor insured back McIntosh and pay to have it shipped back insured? Hell, why don’t you and jetter step up and be good guys and pay the shipping + insurance cost to send the amp to McIntosh, both ways.
Goggle search, Two McIntosh dealers in Chicago Illinois.
Audio Video Interiors of Chicago
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Saturday Audio Exchange
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I have made up my mind about this brand not just this amplifier. To answer to @cleeds I have done only one outlet that does not meet NEC standards which was un-installed completely and is no longer in existence and everything else is back to normal, but the amp is still buzzing. The amp buzz has nothing to do with what I have done with the electrical it just cost me money that’s all, money can be made but the experience I’ve had so far with this brand alone is unforgettable and was unpleasant. After spending so much money and not even one phone call was made back to me that should tell you something. The amp just sits in the corner collecting dust and if you wanna buy it it’s yours for $5K
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