Comparing McIntosh MC462 vs Hypex NC502 objectively

[March Audio]

@March Audio I recall seeing you doing at ftc test on your p252 (nc252 based) amp and it doing 250w @ 4ohm. Am I recalling that correctly? Have you tried that test with your P502 amp?

Yes I have with no problems. Don't have a video of that though.

However it should be noted the FTC test is quite misleading. This is the case for any amp and not just class d. I fully understand it was an attempt to provide a basis for meaningful comparisons between amps power ratings for consumers but it is completely unrepresentative of real world operating conditions and as such no help to the consumer.

As pointed out in a previous post, music has a low rms content so no amp will ever be required to produce its full rms output for 5 minutes. So to pass the test an amp may require extra costly heat sinking which will never be required in real world use. Conversely a design with perfectly adequate heatsinking for real world music use might fail the test. Its bad engineering to design on the basis of having to pass an irrelevant test and ultimatly increases cost to the consumer ( product build and shipping). Note this is a much bigger issue for class A A/B than it is for much more efficient class d.

Burst rating is far more relevant a test than maximum rms IMO.

 

[Dj7675]

Yes I have with no problems. Don't have a video of that though.

However it should be noted the FTC test is quite misleading. This is the case for any amp and not just class d. I fully understand it was an attempt to provide a basis for meaningful comparisons between amps power ratings but it is completely unrepresentative of real world operating conditions. As pointed out in a previous post music has a low rms content so no amp will ever be required to produce its full rms output for 5 minutes. So to pass the test an amp may require extra costly heat sinking which will never be required in real world use. Note this is a much bigger issue for class A A/B than it is for much more efficient class d.

Burst rating is far more relevant a test than rms.

Thanks and I agree with all you have said here. It is still nice that it passes it I have really appreciated your time and info provided.

 

[March Audio]

One comment on this.. on the McIntosh specs, it show the ”maximum total harmonic distortion at .005” Which is at 250mw. Aren’t the harmonic distortion numbers quoted above apples and oranges with the McIntosh showing worst case across the entire band and the P502 showing best case?

The Mc maximum distortion won't be at 250mW so I'm not sure what they are saying there, sounds like it should be minimum.

You need to compare distortion through out the power range. The Hypex graphs, are shown a few posts back. Unfortunately we don't have the Mc.

 

[Dj7675]

@March Audio This from the MC462 measurement was the one I was looking at.l It shows at it worst is .005 (if I am reading it correctly and understanding it correctly). Is this showing .005 at its worst? This is what I think they mean when they say maximum.

 

[March Audio]

@March Audio This from the MC462 measurement was the one I was looking at.l It shows at it worst is .005 (if I am reading it correctly and understanding it correctly). Is this showing .005 at its worst? This is what I think they mean when they say maximum.

Aaah, ok just one thing to point out that graph will be THD + N (SINAD) so its a composit of harmonic distortion and noise. At low signal levels noise dominates over distortion. As you increase the signal level the difference (ratio) between the noise and the signal increases. This is why it falls in the first half of the graph. Over a certain signal level the harmonic distortion starts to rise and becomes dominant over the noise and hence the graph starts to rise until the point where the amp is near clipping and distortion starts to shoot up.

So on that MC462 graph we see that the highest signal to noise and distortion ratio is found at about 115 watts and is 0.0035% which equates to 107dB.

Note that Amir tests at 5 watts which is a far more typical listening level. At 5 watts the MC462 is 0.0008% which equates to 102dB. You can compare this to Amirs tests of other amps.

The MC252 is not as good as the MC462, but we dont have a detailed graph for that so its impossible to tell its overall performance.

So lets look at the P502.

Its best THD+N (1kHz) or SINAD occurs between 5 and 10 watts being about 0.0014% or 97dB.

So yes the MC462 performs better than the P502 in this respect, however the MC462 is not what we are interested in. Its also 9 times the price of the P502 . This is why I said earlier that a more appropriate comparison to the MC462 would be the P451 or P701 monoblocks.

So what we know about the MC252 is this

At 250 mW that is actually the same as the P502. What we dont know is how the graph sits between 250mW and its rated power of 250 watts. It could be better than the P502, but it will probably be worse.

if we described the P502 in the same terms it would be able to remain below 0.005% distortion from 250mW to 500 watts at a 4 ohm load.

At an 8 ohm load it remains below 0.005% between 150mW and 300 watts.

...and yet there is a certain poster, @sirnatealot , who thinks class D manufacturers dont provide any detailed performance information

 

[sirnatealot]

Where did you get this nonsense from? Please cite examples.

You don't sell / manufacture class A/B amps by any chance?

I don't sell any audio gear. You guys like this technology, and I get that. Some of you make it. This technology has been great, and it has many wonderful uses. I'm not storming through any doors, I simply walked by and overheard the chatter. I do have McIntosh equipment, but I also have Marantz equipment and Onkyo equipment and have had many others. There are those that like various specifications and you can always pick them to death.

I am sorry that some of you took it the wrong way, I am not trying to call anyone ignorant (despite a lack of reciprocity there) I simply do not think some of you are familiar with McIntosh core technologies, which like any product, some will like and others won't. This surprised me. I do not ever recall coming across this before. I have no doubt that you can understand them, and that you can teach me a thing or two, but I wish that these things were better understood before we just dove in to compare two very different technologies.

The autoformer- it is an impedance matching transformer, yes it will spec differently depending on which outputs you use, but you know what I meant, it is meant to impedance match the amp to the speakers and gain the associated benefits of that. I thought that was understood when I said "the same".

Power Guard- Yes, I know what clipping sounds like and would never purposely drive an amplifier into that. Knowing what we know about the intensity of sound and the way we hear, it is not really uncommon for a more quiet part to be hundreds of times lower than the louder parts. Take the Interstellar score for example. For whatever reason people in these circles don't appreciate this, but in the OEM car world most everyone has adopted it one way or another so they don't have to replace speakers under warranty. Clipping can occur when you can't even hear it, and that's when tweeters get fried. Cumulative heating on tweeter coils from distortion is a real issue, and it burns up expensive speakers just the same as others. I think the bad assumption here is that any time the amp is in clipping it is intentional and the user should just not do that.

If the amp has powerguard, I can set the volume at whatever and don't have to worry that the next song might have some unknown passage that would fry my speakers before I got to turn it down. I should not have used the word "fear". I should have said irresponsible. I primarily deal with speakers, and I will tell you that I find it irresponsible to use an amplifier without clipping protection at more than .01 of it's rated output for average listening. So if your amp is 350w, that's 3.5w. That's being responsible. And you better hope you know what this level is since there is no way to tell what the amp is putting out.

Now, feel free to continue a conversation about this spec vs that spec (I did skip over a bunch, due to the nature of the class D amp several will be better, no need to even look at it)

And finally, if you own a McIntosh product and want to compare it to another, you should call the factory where they make it, in NY, and ask. They do not rate their components at the industry standard for power output because that industry standard is trash, and like I said it is meaningless. If the specs you want exist, they will give them to you. If the cost of the amplifier is a driving force for you, then 1/7th the cost should be where the conversation ended. It is cheaper. No doubt.

The ironic thing is I meant what I said, I do think these amplifiers have many good uses and I bet eventually someone will ask me what they should get and this will fit the bill, and I will recommend them. If you like McIntosh and their core technologies, this is not for you. That is the point of my post. If the OP seems to be considering trading a 252 for some of these. I do not think that is a wise decision. Not only does he already have the 252, which is a really great amp, but even if this other amp was actually "better" via the specs beaten to death here, it would not represent a noticeable improvement in sound, if even a measurable one once it was running actual speakers. And, as I have said, even if that amplifier can do 350w, it should never be used at more than 3.5w continuous, except in very controlled conditions. I would also place some value on the fact that the McIntosh will always be supported and service parts available by a company that is over 70 years old.

 

[CDMC]

I am sorry that some of you took it the wrong way, I am not trying to call anyone ignorant (despite a lack of reciprocity there) I simply do not think some of you are familiar with McIntosh core technologies, which like any product, some will like and others won't. This surprised me. I do not ever recall coming across this before. I have no doubt that you can understand them, and that you can teach me a thing or two, but I wish that these things were better understood before we just dove in to compare two very different technologies.

But yet you do and rather than address the issues raised in response, you continue with the same baseless claims and deprecating comments. We do understand the "issues" you raised and have addressed them. You have not responded to the evidence and factual information provided. Again, while great marketing, McIntosh's claimed features add little practical value and in the case of the autoformers make zero sense.

The autoformer- it is an impedance matching transformer, yes it will spec differently depending on which outputs you use, but you know what I meant, it is meant to impedance match the amp to the speakers and gain the associated benefits of that. I thought that was understood when I said "the same".

Again, it serves a purpose for tubes with their very high output impedance. It serves no purpose with solid state with a low output impedance, except to raise the output impedance so the speaker load will interact with the amp to cause impedance variations. I have a similar device on my Sunfire Stereo amp that raises the output impedance except Bob Carver didn't give it a fancy name and gave two output options so you could choose if you wanted to use it or not.

Power Guard- Yes, I know what clipping sounds like and would never purposely drive an amplifier into that. Knowing what we know about the intensity of sound and the way we hear, it is not really uncommon for a more quiet part to be hundreds of times lower than the louder parts. Take the Interstellar score for example. For whatever reason people in these circles don't appreciate this, but in the OEM car world most everyone has adopted it one way or another so they don't have to replace speakers under warranty. Clipping can occur when you can't even hear it, and that's when tweeters get fried. Cumulative heating on tweeter coils from distortion is a real issue, and it burns up expensive speakers just the same as others. I think the bad assumption here is that any time the amp is in clipping it is intentional and the user should just not do that.

Yes, car audio, the bastion of sound quality. Yes, they have protection, as you can't hear any distortion at 140db+. In a home environment, if you have adequate power, you should never be clipping, and even when you do, it should not occur at a level that causes damage.

If the amp has powerguard, I can set the volume at whatever and don't have to worry that the next song might have some unknown passage that would fry my speakers before I got to turn it down. I should not have used the word "fear". I should have said irresponsible. I primarily deal with speakers, and I will tell you that I find it irresponsible to use an amplifier without clipping protection at more than .01 of it's rated output for average listening. So if your amp is 350w, that's 3.5w. That's being responsible. And you better hope you know what this level is since there is no way to tell what the amp is putting out.

How did you come to this conclusion? Do you understand that you can calculate the 0dbfs and with modern digital preamps limit the volume so this level is never exceeded and prevent clipping this way?

Now, feel free to continue a conversation about this spec vs that spec (I did skip over a bunch, due to the nature of the class D amp several will be better, no need to even look at it)

Why thank you for your being glib. When actually asked to provide evidence and respond to evidence refuting your claims, all you have done is repeat the same baseless arguements. Your benevolence and kindness allow us to continue the discussion is appreciated.

And finally, if you own a McIntosh product and want to compare it to another, you should call the factory where they make it, in NY, and ask. They do not rate their components at the industry standard for power output because that industry standard is trash, and like I said it is meaningless. If the specs you want exist, they will give them to you. If the cost of the amplifier is a driving force for you, then 1/7th the cost should be where the conversation ended. It is cheaper. No doubt.

Thank you for opening the door. Since you are taking a position, can you please be specific. Please let us know:

1) What industry standards you are referring to?
2) Which of the standards are "trash"?
3) What non industry measurements that McIntosh uses that are informative?
4) Who at McIntosh will provide these mysterious non-trash specs?

The ironic thing is I meant what I said, I do think these amplifiers have many good uses and I bet eventually someone will ask me what they should get and this will fit the bill, and I will recommend them. If you like McIntosh and their core technologies, this is not for you. That is the point of my post. If the OP seems to be considering trading a 252 for some of these. I do not think that is a wise decision. Not only does he already have the 252, which is a really great amp, but even if this other amp was actually "better" via the specs beaten to death here, it would not represent a noticeable improvement in sound, if even a measurable one once it was running actual speakers. And, as I have said, even if that amplifier can do 350w, it should never be used at more than 3.5w continuous, except in very controlled conditions. I would also place some value on the fact that the McIntosh will always be supported and service parts available by a company that is over 70 years old.

So which is it, is there no "noticeable sound" difference, or is there? Why should the amp never be used at more than 3.5w continuous? How do you know that McIntosh will be around in 70 years, much less 5 years? Did you know that McIntosh Laboratories was sold in 2012 to Fine Sounds Group which then changed its name to McIntosh Group. They haven't done a very good job at bringing Audio Research or Wadia back as players with their ownership. Do you think they will do better with McIntosh? Dealer networks that sell McIntosh are dying, how long do you think they will last?

Finally, you made a claim earlier about Class D amps blowing up, capacitors going bad, and catching fire. You were asked to provide support of this. As you have not provided any, it appears you are just making up facts that you believe will support your baseless arguments. If you have some FACTS, please provide them.

 

[March Audio]

But yet you do and rather than address the issues raised in response continue with the same baseless claims and deprecating comments We do understand the "issues" you raised and have addressed them. You have not responded to the evidence and factual information provided. Again, while great marketing, McIntosh's claimed features add little practical value and in the case of the autoformers make zero sense.



Again it serves a purpose for tubes with their very high output impedance. It serves no purpose with solid state with a low output impedance, except to raise the output impedance so the speaker load will interact with the amp to cause impedance variations. I have a similar device on my Sunfire Stereo amp that raises the output impedance except Bob Carver didn't give it a fancy name and gave two output options so you could choose if you wanted to use it or not.



Yes, car audio, the bastion of sound quality. Yes, they have protection, as you can't hear any distortion at 140db+. In a home environment, if you have adequate power, you should never be clipping, and even when you do, it should not occur at a level that causes damage.



How did you come to this conclusion? Do you understand that you can calculate the 0dbfs and with modern digital preamps limit the volume so this level is never exceeded and prevent clipping this way?



Why thank you for your being glib when actually asked to provide evidence and provided evidence refuting your claims. Your benevolence and kindness allow us to continue the discussion is appreciated.



Thank you for opening the door. Since you are taking a position, can you please be specific. Please let us know:

1) What industry standards you are referring to?
2) Which of the standards are "trash"?
3) What non industry measurements that McIntosh uses that are informative?
4) Who at McIntosh will provide these mysterious non-trash specs?



So which is it, is there no "noticeable sound" difference, or is there? Why should the amp never be used at more than 3.5w continuous? How do you know that McIntosh will be around in 70 years, much less 5 years? Did you know that McIntosh Laboratories was sold in 2012 to Fine Sounds Group which then changed its name to McIntosh Group. They haven't done a very good job at bringing Audio Research or Wadia back as players with their ownership. Do you think they will do better with McIntosh? Dealer networks that sell McIntosh are dying, how long do you think they will last?

Finally, you made a claim earlier about Class D amps blowing up, capacitors going bad, and catching fire. You were asked to provide support of this. As you have not provided any, it appears you are just making up facts that you believe will support your baseless arguments. If you have some FACTS, please provide them.

I was going to reply to sirnatealot but your reply covered it all really. Thank you.

 

[GXAlan]

In a home environment, if you have adequate power, you should never be clipping, and even when you do, it should not occur at a level that causes damage.

The Benchmark AHB2 has been reported by many users here as flashing the clipping light when run in stereo mode (which is why bridged AHB2's can be popular). It really depends on room size/speaker efficiency. There is a post I made a year or two ago looking at average "living room sizes" in different countries (and different states in the USA) and then showing how an efficient speaker or inefficient speaker (both with good preference scores) could translate into vastly different power requirements for an amplifier if you needed 85 dB averages with 105 dB peaks.

How did you come to this conclusion? Do you understand that you can calculate the 0dbfs and with modern digital preamps limit the volume so this level is never exceeded and prevent clipping this way?

Needle drops...
Topping DAC/Pre-amps that forget their volume setting...

1) What industry standards you are referring to?
2) Which of the standards are "trash"?
3) What non industry measurements that McIntosh uses that are informative?
4) Who at McIntosh will provide these mysterious non-trash specs?

One thing that McIntosh has historically stated is that their specifications represent "the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you that the MC 2105 you buy must be capable of performance at or exceeding these limits or you get your money back. McIntosh is the only manufacturer that make this guarantee. " This was in the 1960's and other manufacturers have followed that guarantee.

When talking about intermodulation distortion, for example, instead of going with CCIF or established standards, they historically stated and continue to talk about
"0.25% if instantaneous peak power output is 210 watts or less per channel with both channels operating for any combination of frequencies 20 Hz to 20,000 Hz"

If you look at the current product line like the MC611, when listing distortion, they state

"The distortion limits for the MC611 are no more than 0.005% at rated power output for all frequencies from 20Hz to 20,000Hz. Typical performance at mid frequencies is less than 0.002%." 0.005% THD+N = -86 dB SINAD

If we look at the NCx500 you can see that at 15 kHz, 40 watts, it's already worse than McIntosh. People talk about 1 kHz distortion mostly.

PowerGuard is configured to limit distortion to 0.3% even though most would say 1% is the point of clipping. This is a nice way to sell bigger amplifiers, of course, but is one measurement that is unique and not necessarily "wrong." I couldn't find what distortion level the AHB2 treats as "some clipping." My understanding is that PowerGuard activates as soon as there is anything that clips to 0.3% THD but if you had a 14 dB overdrive, presumably the reduction is only good enough to get it down to 2%.

So which is it, is there no "noticeable sound" difference, or is there? Why should the amp never be used at more than 3.5w continuous? How do you know that McIntosh will be around in 70 years, much less 5 years? Did you know that McIntosh Laboratories was sold in 2012 to Fine Sounds Group which then changed its name to McIntosh Group. They haven't done a very good job at bringing Audio Research or Wadia back as players with their ownership. Do you think they will do better with McIntosh? Dealer networks that sell McIntosh are dying, how long do you think they will last?

We don't know if McIntosh will be around in 70 years or not. The real question is if the company is profitable not if it's a "player". I would assume that distribution at BestBuy/Magnolia, "premium priced" products, US manufacturing that reduces supply chain challenges, and brand equity that's leveraged in Jeep vehicles certainly puts them in a better position than many other companies.

The only McIntosh product I own currently is the MPM4000. I did have a complete vintage stack MX113, MI-3, MC2105 as well as a modern tube amp, the MC2102, all of which were sold for reasons other than sound quality. My main amp is the Marantz PM-10 which has a quartet of HypeX NC500OEM modules, so I don't think I'm anti-Class D or blind to McIntosh.

If I won the lottery tomorrow, I'd probably re-invest in some McIntosh gear. Their audio products (not their lifestyle products) work great and measure well.

 

[Matias]

If we look at the NCx500 you can see that at 15 kHz, 40 watts, it's already worse than McIntosh. People talk about 1 kHz distortion mostly.

It's because other people think 15 kHz THD+N means 15 kHz itself being distorted, but it is not, but rather harmonic distortions from it being increased. And that would be 30 kHz for 2nd harmonic, 45 kHz for 3rd harmonic and so forth. Meaning: inaudible. Specially considering equal loudness contours (Fletcher-Munson curves).

On the other hand try searching for IMD measurements in high frequencies, like 18+19 kHz tones. There you can see how it spreads down into audible range. Here are a few:

On Class D Amplifiers Measurements

I/O measurements of Hypex NC252MP step response/rise time and of input/output spectra with 20kHz square signal. Staying technical, showing parameters and behaviour. Not mentioning audibility. Step response 20kHz square I/O spectra (interesting output noise modulation) I’m amazed it’s that...

www.audiosciencereview.com

 

[restorer-john]

My understanding is that PowerGuard activates as soon as there is anything that clips to 0.3% THD but if you had a 14 dB overdrive, presumably the reduction is only good enough to get it down to 2%

You need to ask McIntosh how they are implementing it these days.

Their old powerguard was realtively simple and yet very clever. It attenuated the input to the power amplifier using an LED and an LDR.

 

[GXAlan]

You need to ask McIntosh how they are implementing it these days.

Their old powerguard was realtively simple and yet very clever. It attenuated the input to the power amplifier using an LED and an LDR.

Yeah, they don't give as many details nowadays although you'd expect any patents for the original PowerGuard to have long expired.

For the MC611 and MC462, they do specify the 0.3% distortion threshold.

https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/mc611om02.pdf?rev=ffad7c36757a45648111fa78161078ae&revision=ffad7c36-757a-4564-8111-fa78161078ae

https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/mc462om01.pdf?rev=77b7745a7d80404ebcf1f575e64585ba&revision=77b7745a-7d80-404e-bcf1-f575e64585ba

For their new "Power Guard Screen Grid Sensor" it's not as clear. It also attenuates the INPUT though.

https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/MC451-OM-24118600.pdf?rev=93003de3789f4503802ae5e7a4383463&revision=93003de3-789f-4503-802a-e5e7a4383463

Meaning: inaudible. Specially considering equal loudness contours (Fletcher-Munson curves).

Agree on that standpoint. We reached inaudible ~43 years ago.

Kenwood L-08M Monoblock Amplifier (Vintage Review)

Kenwood L-08M Monoblock Amplifier Review (Vintage Gear; QuirkAudio restored) Where were you in 1980? In Tokyo, Japan, a small team of engineers released the most sophisticated amplifier of its time... A bit of history In the 1970's, an elite team of veteran Trio-Kenwood engineers left the...

www.audiosciencereview.com

and as I said, my current reference unit is the Marantz PM-10 even though it measures worse than the PM-11s2 that I'm selling.

 

[radix]

For their new "Power Guard Screen Grid Sensor" it's not as clear. It also attenuates the INPUT though.

https://www.mcintoshlabs.com/-/media/Files/mcintoshlabs/DocumentMaster/us/MC451-OM-24118600.pdf?rev=93003de3789f4503802ae5e7a4383463&revision=93003de3-789f-4503-802a-e5e7a4383463

It never registered with me that that the 451 has SS LF and tube HF amps for bi-amping with its own a crossover. Though for $14k each ($28k for stereo), that's not really affordable.

 

[steve59]

I'm impressed with the first watt coming out of the mc611's! Driving the kef blades the difference going from a 300 wpc class a/b int that came close to 600 watts into 4 ohms and more into 2 still needed to be turned up a bit to bring some dynamics to the music. In comparison the mc611 with the meters bouncing between .6-6 watts the blades sound like different speakers, so much more everything. I've heard such differences with other demanding speakers, but not all and def not always obvious. I'm new to Mac, but am all in.

 

[fpitas]

I would never trade a McIntosh for a class D.

I agree! I'd sell the McIntosh and buy a nice class D, and pocket the rest

 

[steve59]

I agree! I'd sell the McIntosh and buy a nice class D, and pocket the rest

A close friend of mine owns Klipsch speakers, the Lascala's and big klipschhorn's and those speakers don't seem to need any fussing over power source. Mac would be window dressing in his system. In my system the Mac gear makes the system sing.