MC8207 Transformer Buzzing

[TomIV]

Oh and one more thing, how many of you know how to measure correctly for DC Offset on your AC line, or how many of your electricians know that?

We are the consumer, the customer, we are not suppose to do this things all we need to do is pay the bill and be happy, that's why they are called engineers to figure things, that's why we pay the big money. From now on you won't hear from me about this thread and amp any more because it is not worth my time and money to go any further with this matter.

Good luck to all of you that have the same problem you would have to learn to live with it.

[cleeds]

Originally Posted by TomIV

... the problem is the buzz, it is very loud ... My problem is with MC, because they know this problem exist and has been known for more than 10 years and I feel since they are the engineers that they needed to come up with a solution ... my case was handled by MC and my dealer is the worse I have had ... I guess $30K that I spent on MC gear is peanuts to them to not care ... About returning the amp, it is over their return policy so I am out of luck there ... So there you go and tell me what do you guys think ...

Your amp was under warranty, yet you wouldn't return it to McIntosh (or an authorized service center) to determine the cause of the issue. Instead, you prefer to conclude the amplifier is defective by design. You could be correct, but it's just speculation on your part.

Freight costs are one of our hobby's "dirty little secrets," and sometimes there's no escape. In your case, with $30K spent, it seems worthwhile to ship it back to Binghamton or - if you really don't trust them - take it to a local authorized service center. Only then will you know for sure the exact root of this problem.

[Poppyhome]

Various noises from ones stereo system typically aren't noticed until one becomes a so call "Audiophile".

Transformer hum/buzz can happen to many amps and is not isolated to McIntosh. Google Bryston amp buzz or any manufacturer for that fact, and see for yourself......................... All my previous amps — Krell, Classe, and Outlaw had some type of noise more or less. Since McIntosh is the most iconic and best known hi end stereo manufacture, you might hear more reports because they are the top dog.

The MC8207 is very similar and based on the MC207 platform which has been around since 2004. If there was a design issue, I'm sure McIntosh would have addressed it and wouldn't be making it for 15+ years. Not many manufactures making the same amp Model for that length of time.

For years I always had a buzz upon turn on from my MC207. Van Alstines HumDinger did not fix my buzz. I decided to try the Emotiva CMX-2 per Ivan's recommendation, and low and behold all noises disappeared. I also have my CMX-2 plugged into my PS Audio Quintet. Why the Van Alstine HumDinger didn't fix my buzz and the Emotive CMX-2 did may be attributed to some extra noise filtration in the CMX-2.

I believe TomIV has also noted the buzz did diminish with the CMX-2, so he is getting somewhere.

Ron

[c_dk]

This copied off the Plitron site. Noisy toroidal transformers have been a known issue for decades.....Mac engineering should address this not shuffle this guy off.

Rod Elliot wrote a proposed solution a decade ago.

Plitrons marketing hype is below.

LNTIt also represents the culmination of years of research at PLITRON into the causes and nature of acoustic noise in magnetic elements and the methods for improvement. An important side benefit of this technology is that inrush currents are also greatly reduced. Over the past 25 years, toroidal transformers have replaced conventional transformers in many applications because, among many other benefits, they are quieter under normal conditions. But, because of the their highly efficient nature, standard toroidal transformers become noisy under adverse line conditions, such as overvoltage and DC offset, (and tend to draw high inrush currents during start-up). With increasingly deteriorating power lines over the years, these adverse conditions are becoming more prevalent. PLITRON LONO™ toroidal transformers suit a variety of applications, but the features of these products are probably best utilized in the demanding Hi-End Audio industry, where growling transformers can represent a huge bear of a problem.
Design

The acoustic performance of transformers is calculated and specified during the design stage. In custom applications, customer engineers work closely with the Plitron design team to establish acceptable performance limits and define specifications.
Noise measurement system

Under four adverse line conditions, spectrum analysis of the noise performance is verified using Plitron’s standardized Noise Testing Chamber. Results are graphed as Sound Pressure Levels (SPL) in decibels (dB) vs. frequency (20 Hz to 10Khz) and assigned a Noise Criterion (NC) curve number. The NC specification is internationally recognized and describes noise levels in dB SPL. For reference, a good recording studio’s noise level is typically NC 15 to ensure a virtually silent noise floor, while in offices NC 30 is usual. LONO™ transformers measured in our Noise Test Chamber under adverse mains conditions produce less than NC 19 at 1 metre distance. At 2 metres they produce less than NC 13. Every doubling of distance results in 6 dB reduction. With nominal line conditions, LONO™ transformers produce NC 10 or less at 1 metre. For more detailed information about this new technology and our measurement system, request Plitron’s White Paper on Transformer Noise. Reduced In-Rush Current PLITRON LONO™ transformers provide lower inrush currents, typically 40% less than standard toroidal transformers. This feature avoids nuisance fuse interruption, can reduce or eliminate the requirement for external devises used for inrush, and allow lower current rated power switches.
Related Information

Also see Measuring Acoustic Noise Emitted by Power Transformers presented at the 109th Convention of the Audio Engineering Society. This preprint was prepared by Menno van der Veen and the research staff at PLITRON. Check out the product line: Low Noise Power Transformers for Solid State Amps.

[cleeds]

Originally Posted by c_dk

... Mac engineering should address this not shuffle this guy off ...

There is zero first-hand evidence that Mac has been unresponsive. In fact, the customer has stated that he will not return the amplifier to McIntosh or an authorized service center for evaluation under warranty. That really makes him at least partly responsible for the problem.

[Masterlu]

Originally Posted by TomIV

Cleeds why am I responsible to pay for shipping dude, get your head out of your ass for once, and whatever you say is irrelevant because the guys at Audiogon exposed who you are and what you do so no need to take any advice form you at all because you have given none.

And no I am not gonna return the amp I am just gonna burn it for fun, since I have plenty of money I don't care, what are we gonna play the cat and the mouse and he said she said bullcrap. I am done with this brand and like I said there is always the Japanese that are willing to go the extra mile to make customers happy.

Well that’s a fast way to get Banned here on AA.

[Poppyhome]

Remember this is the The Friendly Forum for High-End Audio.

Ron

[stereo_5]

It is HIS money and amp and if he is so disgusted that the dealer and manufacturer washed their hands from all of this, then he has the right to not send the unit back. He tried the Emotiva noise blocker and it didn't work. He has a new house with new wiring and dedicated circuits for the system and at this point he feels that he doesn't want to deal with it any longer. Who are we to judge him for the way he feels? Personally, I feel bad for the guy because he has an amp with such a loud buzz that he can hear it across the room from his listening chair. I don't know what the amp cost but I am sure it is a lot of $$$ to have sitting in the corner being unused. I really feel that in order to instore goodwill, either the dealer should give him his money back, or the manufacturer should do something to make the guy whole.

Banning him solves nothing.

[Poppyhome]

Originally Posted by stereo_5

I must say, if you read the Audiogon thread, Cleeds would not let up on this guy. It is HIS money and amp and if he is so disgusted that the dealer and manufacturer washed their hands from all of this, then he has the right to not send the unit back. He tried the Emtiva noise blocker and it didn't work. He has a new house with new wiring and dedicated circuits for the system and at this point he feels that he doesn't want to deal with it any longer. Who are we to judge him for the way he feels? Cleeds on the other hand, has been badgering him on Audiogon over this for days at a time, so the guy blew up at him. Personally, I feel bad for the guy because he has an amp with such a loud buzz that he can hear it across the room from his listening chair. I don't know what the amp cost butI am sure it is a lot of$$$ to have sitting in the corner being unused. I really feel that in order to instore goodwill, either the dealer should give him his money back, or the manufacturer should do something to make the guy whole.

Banning him solves nothing.

I personally don't appreciate reading the language and aggressive tone that's allowed on other forums and appreciate Ivan stepping in quickly before it got out of hand.

.


Ron

[Masterlu]

Originally Posted by stereo_5

I must say, if you read the Audiogon thread, Cleeds would not let up on this guy. It is HIS money and amp and if he is so disgusted that the dealer and manufacturer washed their hands from all of this, then he has the right to not send the unit back. He tried the Emtiva noise blocker and it didn't work. He has a new house with new wiring and dedicated circuits for the system and at this point he feels that he doesn't want to deal with it any longer. Who are we to judge him for the way he feels? Cleeds on the other hand, has been badgering him on Audiogon over this for days at a time, so the guy blew up at him. Personally, I feel bad for the guy because he has an amp with such a loud buzz that he can hear it across the room from his listening chair. I don't know what the amp cost butI am sure it is a lot of$$$ to have sitting in the corner being unused. I really feel that in order to instore goodwill, either the dealer should give him his money back, or the manufacturer should do something to make the guy whole.

Banning him solves nothing.

I consider AA an extension of my home. Folks are kindly invited, but only remain if they behave civily, are respectful to others, and abide by the forum rules.

What happens elsewhere is of no concern to me. Banning him here solves everything as far as I’m concerned.