DC Offset Blocker/Killer - where to buy in the USA - for MC8207

[damacman]

In this forum, we're pretty hardcore Mc enthusiasts - for various reasons. You obviously chose McIntosh over all other brands when you plunked down your money. It would be nice if you were able to arrive at a solution that would allow you to be satisfied with your purchase. It's unfortunate that you had to come here to find it.

 

[joeinid]

I’ve been around the block many times. I’ve also had McIntosh several times. I’m back to McIntosh because I love the way my current McIntosh pieces sound. Now I always use a dc blocking power conditioner on everything regardless of humming or not. I honestly love my system now.

 

[c_dk]

Soundstage!dB-the high- end mythology of toroidal transformers makes some interesting points about the "lemmingesce" plunge by many high end audio companies over the toriod cliff vs. the EI transformer in theater applications.

The article does seem to point to this DC offset issue being caused by the general AC transmission grid's susceptibilities to it.

 

[TomIV]

I hope to come to a solution too, out of all the brands out there I chose McIntosh because that's what made me smile when I saw one or listen to one and after years of saving and wanting one or two and three pieces time came for me to buy my dream audio equipment to come to find out that both the MC8207 and the MC462 were not perfect out of the box. Here I have to mention my wife as well who gave me the green light to purchase this equipment, BUT imagine how I felt when my wife heard the buzz and the loose parts on the MC462 and said to me What The Fk did you spend all this money on? And the way I was treated from the dealer to the manufacturer. And than I have my daughter who is siding with my wife, do you know what Mac is in their eyes now - nothing.
I feel like _ _ _ _ _ _ _ fill in the blank

 

[TomIV]

Oh and all the lies I told my family why am I bringing all these electricians to fix our power when there is no problem at all and spend more money, oh and why I needed an expensive power conditioner to "protect my new equipment".

I will keep my MC462 and C52 for sure and the AV8805 but the 8207 has to be either replaced with a better one or replace with another brand or something.

Mc would always be in my heart no matter what I say and how much I hate it right now but I am hoping that things would work out at the end

And I am sorry if I offended some of you Mc users...

 

[PanheadXR290]

This problem is not specific to McIntosh, fortunately or unfortunately. I’ve experienced it with many manufacturers. I don’t know why they can’t just design a dc blocker into the amp and be done with it, but no one else does either.

I know you spent a lot on the amp but if a dc blocker works, be happy.

I’ve given up assigning blame or working myself into a frenzy.

My system sounds great and if I need a dc blocker, so be it.

ps. If you don’t want to keep the CMX-2, please don’t feel obligated. I’m just looking to help.

I absolutely love my Emotiva CMX units ,when they are in stock I grab extras for TVs and such ,I'm in the process of getting my brother 2 CMX-2s and 1 CMX-6 once they clear customs .

 

[joeinid]

Tom,

Reading these posts makes it clear. I’m sorry, but you are right, and do not apologize. The 462 should have been replaced too. Geez. That’s terrible.

Oh and all the lies I told my family why am I bringing all these electricians to fix our power when there is no problem at all and spend more money, oh and why I needed an expensive power conditioner to "protect my new equipment".

I will keep my MC462 and C52 for sure and the AV8805 but the 8207 has to be either replaced with a better one or replace with another brand or something.

Mc would always be in my heart no matter what I say and how much I hate it right now but I am hoping that things would work out at the end

And I am sorry if I offended some of you Mc users...

I hope to come to a solution too, out of all the brands out there I chose McIntosh because that's what made me smile when I saw one or listen to one and after years of saving and wanting one or two and three pieces time came for me to buy my dream audio equipment to come to find out that both the MC8207 and the MC462 were not perfect out of the box. Here I have to mention my wife as well who gave me the green light to purchase this equipment, BUT imagine how I felt when my wife heard the buzz and the loose parts on the MC462 and said to me What The Fk did you spend all this money on? And the way I was treated from the dealer to the manufacturer. And than I have my daughter who is siding with my wife, do you know what Mac is in their eyes now - nothing.
I feel like _ _ _ _ _ _ _ fill in the blank

 

[clinic-audio]

Hello TOM

I am not affilied in any way to Mc Intosh labs , I just wanted to help and explain you what is happening in your house . I have met many problem with specific troubles during these 42 years and not only with MC INTOSH amplifiers . I have refixed (the way they schould be) MC INTOSH , JEFF ROWLAND , MUSICAL FIDELITY "monsters" with very very big toroidal power transformers with story of "DC" on AC for some , that's why I know very well the problem .
I was (before to post my schematic ) probably one rare person to cance problem like this in France with "huming toroidal power transformers " now , all my competitors will have the solution to theire problems but I post it anyway to share my knowledge of this problem with the AK community . I will loose my "exclusivity" but it is not important .

TOM
I understand your position , but you did not make the test I asked you to do . Everybody was intesrested by the result of these test but you think you have lost enough time with that .
What I can tell you is that if I met this kind of problem I will find who is making this mess in my house because you know that this is not coming from your MCINTOSH . Any other big amp with the same power supply (toroidal power transformer) with vibrate with the same intensity and maybe worse ! Make the complete test may need a day to find but it is very interesting to learn who is making this in your house !

Why MCINTOSH use toroidal power transformer in this unit ? It is simple : not enough place with a normal power transformer and also a toroidal transformer for this size is the best choice regarding vibrations (when there is problem of DC ) .

You have decided to ask for refund , fine , but if you buy another unit , follow my advise to use one power amplifier with normal power transformer in .Making the requested test will be difficult once your MC8207 will be gone ...

 

[TomIV]

Hello everybody

No , I have explained some pages ago that this phenomenon will affect only toroidal power transformers
Tom , now you know that the MC INTOSH power transformer is not guilty , you can make some research to know from where it is coming from .
It will be very interesting for you to know even if it takes time to find . Nobody here can do it instead you .
1) disconnect everything from your AC line (it should stay nothing connected , nothing )
2) first connect your amplifier without this " DC Blocker " and switch it on
3) connect your microwave and listen if you have noise in your MCINTOSH
4) do the same with all your electrical equipment one by one untill the "noise " is coming back in your transformer
5) then you will know now who is bringing the mess in your home but certainly not your MC INTOSH amplifier

I am sure that many AK members are waiting for your answer

If you are talking about this test, I have already done it and have posted in my previous posts. I switched all breakers to off except the one for the amp or the outlet where the amp was plugged into. The buzz was still there. I started turning on the breakers on one at a time and nothing changed buzz was the same all the time. I did this test again this morning and turned the microwave on and off but the buzz was the same no matter if microwave was working or not. Also had my wife turn on the washer and dryer, I had the furnace and ac on and off and nothing make the buzz go away or worse it stayed the same. I also bought a circuit tester to check my outlets and all my outlets checked out correct. I do not have open neutrals, grounds or hots. I bought a multi meter that measured DC in mV and stick probes one in the neutral and one in the phase and the multi meter red 0.9mV.
There was one or two time where when I turned the amp On ti was quite for like 5-10 seconds to which I thought the buzz was gonna and than boom it came back and it stayed On.
Was there another test that you wanted me to do?

 

[joeinid]

Looks like FedEx delivered the CMX-2 a day earlier than I expected. Fingers crossed for some relief for Tom. I’m hoping it quiets the amp down, regardless if he keeps it or not.

 

[damacman]

Joe - again, very kind of you to do this.

Tom - we’re on pins and needles here!

 

[joeinid]

OMG! I am too. These have worked for me, hope for Tom as well.

 

[TomIV]

Looks like FedEx delivered the CMX-2 a day earlier than I expected. Fingers crossed for some relief for Tom. I’m hoping it quiets the amp down, regardless if he keeps it or not.

Yeaaaahhh, just saw it at my front door and was thinking to myself what did I ordered this time, got confused for a little bit. I will let it sit room temp for like 30 minutes and will try it fingers crossed, my legs are shaking

 

[joeinid]

Hahahaha, don’t be scared.

 

[TomIV]

Sooooo, here is the link to the youtube video I have uploaded and let me hear your thoughts... Hint: There is an improvement but not completely gone.

0-30 seconds plugged in the Emotiva CMX-2, from 35 to 60 sec is plugged into the wall outlet

 

[EngineerNate]

Tom has tried:

1. Turning off everything in his house but the amp, at the breaker.
2. Installing dedicated circuits with their own isolated grounds.
3. More than one $$$ power conditioner, including one meant specifically to block DC (The Emotiva).
4. Going over to someone else's house to see if the problem persists.

All four tests have resulted in a humming amplifier.

I dunno what more anyone could ask from the guy on this issue. There's clearly a problem with the amp if none of the above fix the problem.

 

[joeinid]

Ok, I see now

 

[joeinid]

Well, I expected a slam dunk. It’s not entirely gone, so it seems. I’d love to try my humbusters or 948 conditioner to be sure. My original amps that started my awareness and frustration needed 2 dc blockers in series. In series! Insane. They were not McIntosh amps.

Ps The amp needs to be returned and an alternative solution should be found. I’m sorry to say.

 

[kevzep]

Wow, my Crowns are quieter than that by a long shot, and I have 30mV of DC on my AC line.....
Screw that for a joke!!
That is bad..

 

[clinic-audio]

Tom has tried:

1. Turning off everything in his house but the amp, at the breaker. I don't think that EVERYTHING was disconnected as I expected but TOM said yes , so ...
2. Installing dedicated circuits with their own isolated grounds. This is not 100% necessary but if you want to do it , you can (not necessary at all in my point of view )
3. More than one $$$ power conditioner, including one meant specifically to block DC (The Emotiva). Power conditioner is not necessary but Emotiva may cancel trouble (depending of the intensity of the phenomenon )
4. Going over to someone else's house to see if the problem persists. No , this is silly to think that, because if the closer neighbor has the guilty switching power supply at him he may give "contamination " to all people connected to the same line ! and this is the case and may explain many things

why don't you talk about the fact that this "humming amplifier " is not making any noise at the dealer location ? Can you explain me this ?

I am ready to read your explanations