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Recommedation for amplifier literature data

B

barsur

Active Member
We all know that the specification from Mcintosh amplifiers are very conservative. One example for this is the MC 452, which is rated 450 Watts per channel in 2,4 and 8 Ohms.
As you can sea in a review from a italian audio magazine the meassured data are far more higher. The came up with a maximum of 2*1.186 Watts in 4 Ohms. Also very interesting that they tested the power for every connection (2,4 and 8 Ohm connection).

Here is the link: http://www.mpielectronic.com/NewsFiles/McIntosch C50-MC452_AR-Giugno2011.pdf

What is more important, that the specified data from Mcintosh from 450 Watts in 2,4 and 8 Ohms are only possible if you switch the 2,4 and 8 Ohm connectors. But this is not very practical and we all know that the impedance curve of a loudspeaker will never be flat.

For that reason my proposal to improve the literatur data.
It would be very nice and helpful, if Mcintosh can specifie the power output for every connection. For example:

8 Ohm connector has 450 Watt on 8 Ohms; 600 Watt on 4 Ohms and 300 Watts on 2 Ohms.
4 Ohm connector has 300 Watt on 8 Ohms; 450 Watt on 4 Ohms and 550 Watts on 2 Ohms.
2 Ohm connector has 150Watt on 8 Ohms; 300 Watt on 4 Ohms and 450 Watts on 2 Ohms.

What do you think Ron, could this be possible?
Bye
Martin
 
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You need to read Sid Coderman's autoformer white paper (posted in Mac Tech sticky) to understand why this incorrect usage will never be supported.
 
You need to read Sid Coderman's autoformer white paper (posted in Mac Tech sticky) to understand why this incorrect usage will never be supported.
Click to expand...
I don´t understand, why this is a incorrect usage. You can connect your loudspeakers only with one connector (2,4 or 8 Ohms), but your loudspeaker impendance will never be flat for this connection. But maybe my english is too bad to really explain what I mean.

For example: I put my Linn loudspeakers on the 8 Ohm connector from the MC 452. But the Linn loudspeaker impedance will vary between 3,2 Ohm till 17 Ohm. So it would be very nice if Mcintosh can say in their owner manual what is the exact output power (for 2,4 and 8 Ohm) on the 8 Ohm connection. And actually I know a lot of Mcintosh owners, who feel exactly the same in this issue.

Best regards
Martin
 
You do not listen to one tone at a time, therefore the combination of frequencies add up to a complex impedance which is in series with the autoformer.

The autoformer gives the output devices an optimum load SELECTED by the designer for best transistor performance.

Sid Coderman chose a 3 ohm load (3,2 to be exact) as the optimum load for the MJ15003/4s used in the MC2255. They wound an autotransformer accordingly.

It is expensive to manufacture autoformers so most companies do not...they buy advertising instead.
 
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Okay, thanks a lot for your expanation. I read also the white paper from Sid Coderman. Very interessting, thanks. But I think it doesn´t answer my question. On a 8 Ohm tap of the MC 452, you know, that you will get at least 450 Watts per channel. But the owner manual doesn´t say how much power output you will get on a 8 Ohm tap for 4 Ohm (I hope you understand me). In some Italian and German stereo magazines, they measure this, for example in the link before.
The measured power output on a 8 Ohm tap for 4 Ohms was far higher than 450 Watt. So it would be great if Mcintosh could provide us with this data in the owner manual.

Bye

Martin
 
Martin,

The shift between loads on any given tap will be close to 3dB.If the measurements are as you quote then the testing proceedure was inaccurate. MC452 makes far more power than specified but you need a bench set up for high power testing to measure.
You might want to look up Hi-Fi News testing of a McIntosh amp as an example.

Thanks.
Ron-C
 
Thanks a lot Ron for your explanation. The quote which I posted were only examples.

The real measured output power figures for the MC 452 in the review are:

8 Ohm tap has 604 Watt on 8 Ohms; 940 Watt on 4 Ohms and ca 400 Watts on 2 Ohms.
4 Ohm tap has 379 Watt on 8 Ohms; 637 Watt on 4 Ohms and ca. 900 Watts on 2 Ohms.
2 Ohm tap has 193 Watt on 8 Ohms; 342 Watt on 4 Ohms and ca. 600 Watts on 2 Ohms.

So I think it is less than 3dB the shift between loads. But never mind, but why doesn´t provide us Mcintosh with this data?

Bye

Martin
 
Read the United States Federal Trade Commissions rules for advertising amp power....because you are reading advertising not engineering journals.

Good or bad (amp companies adverstising agencies have chaffed under these rules for decades) they are the rules for the USA. I believe the EIA has their own different rules for Europe.
 
The amplifiers specifications are stated for a known set of loads and testing standard. Real world performance will differ of course and it will vary in each system as all of the variables add up.

thanks,
Ron-C
 
Hello Ron

Thanks for your answer. But maybe Mcintosh can rethink their position.
Look for example how perfect shows Lamm their amplifier power output specitication, also subdivided for the different taps (high and low impendance):http://www.lammindustries.com/PRODUCTS/m12spec.html

So for us as users, with this specification we could work better.

Best regards

Martin
 
C_dk, you hit the nail on the head. Everyone will just have to be satisfied with better than advertised performance.

Thanks,
Ron-C
 
Wilson Audio Sasha on 8 Ohm tap

I would be also very interested to have this information. I have MC252/Wilson Audio Sasha combination hooked up on 8 Ohm tap. Wilson Audio Sasha drops to 2 Ohms. So I would like to know how much output power do I have from 8Ohm tap on 2 Ohm. I think it is a great idea to put this in the specification data. Or I have to buy a Lamm.:tongue:
 
More trolling?????? What frequency or more correctly what complex musical note with harmonics and sub harmonics do propose to use as a test?

Lamm uses a voltage switch like many theater receivers to allow it to drop the transformers voltage to increase the amperage....been done for years.
 
Hello Celm123

Hello Celm123
I think this review will answer your question:http://www.mpielectronic.com/NewsFiles/McIntosh MC252 _ AR-Aprile-2009.pdf

It is a little bit difficult to read but the measured power output on the 8 Ohm tap for the MC 252 is:

8 Ohm tap has 354 Watt on 8 Ohms; 516 Watt on 4 Ohms and ca 200 Watts on 2 Ohms

Ofcourse I don´t know, how the magazine measured the data (which frequency, distortion etc). It is not mentioned in the test. But I hope it will help you a little bit and I hope that c_dk will not to upset with me again.

Best regards

Martin
 
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Great, exactely what I was looking for. Thanks. Maybe I hook up the Wilson Audio on the 4 Ohm tap. But 8 Ohm tap sounds better.
 
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