ATI AT522NC Stereo Amplifier Review

[amirm]

Why not forget the sweep and just do spot frequencies? Less stressful on these poor little amplifiers, the time taken would be much less and they won't go bang on your bench.

Say 40Hz, 100Hz, 10KHz and 20KHz?

Makes for an uglier graph. It has 20 steps right now.

 

[amirm]

If you look at big companies like Harman, with their flagship Mark Levinson lineup they choose to release very little measurement data on the products. And Harman is worshipped as the pinnacle of audio science around here. But nobody ever talks about that.

The research we talk about came from work of Dr. Toole and Olive while at Canadian NRC. It later got more developed in the advanced R&D group at Harman but it was not invented by Harman. Nor was it adopted broadly within Harman for a while. JBL for example came kicking and screaming.

Harman marketing thinks releasing such data is "confusing" to customers and hence the reason they don't release spin data for their speaker either, even though that is cornerstone of the above research.

Net, net, no one here is worshipping harman. They are worshipping the research and key people behind it. Don't try to spin it some other way.

 

[Audiocrusader]

The research we talk about came from work of Dr. Toole and Olive while at Canadian NRC. It later got more developed in the advanced R&D group at Harman but it was not invented by Harman. Nor was it adopted broadly within Harman for a while. JBL for example came kicking and screaming.

Harman marketing thinks releasing such data is "confusing" to customers and hence the reason they don't release spin data for their speaker either, even though that is cornerstone of the above research.

Net, net, no one here is worshipping harman. They are worshipping the research and key people behind it. Don't try to spin it some other way.

Confusing to customers? So the pinnacle of audio science decides to withhold data because they don't want to confuse their clients. Or is it because the data completely sucks?

Well they say you are what you eat. So what does the king of audio have in his system? And how does it stack up against the best tested around here? And what was the total cost? The leader of a forum like this should have nothing but the best. And back it up as well.

 

[restorer-john]

You still don't seem to realize that other than the NC-400, Hypex sells OEM subcomponents for professional amp builders to use as a subsection of their amplifier products. These are not turnkey, ready to go amplifiers. When you read the datasheet of a DAC chip, you don't see the exact same specs that will be seen in every DAC on the market that uses the chip. It's up to the manufacturer who incorporates the module into their design to release whatever kind of test data they want. The reason the input impedance and gain is so low is because it's not a finished product! These modules are designed this way so the OEM can make their own input buffers and voice the amplifiers to whatever taste they want, or try to make them as neutral as they want. This is how OEM's differentiate their products from their competitors. If any OEM finds the Hypex datasheet is insufficient for their needs, they can run whatever battery of tests they want during the evaluation period of the modules. And whatever data the OEM decides to share with their clients is all based on the marketing strategy they choose to go with.

Do you really think I don't know that? Come on!

If you look at big companies like Harman, with their flagship Mark Levinson lineup they choose to release very little measurement data on the products. And Harman is worshipped as the pinnacle of audio science around here. But nobody ever talks about that.

I agree, there is some crazy blind following of Harman (Samsung) based on ancient history, the brands they sucked up, and some very good products, research and developments they did or presided over in the past.

But people who buy based on group-think are destined to get what they deserve. I do care when established standards are eroded, specifications are incomplete or deceptive and performance doesn't measure up to the hype.

 

[March Audio]

Exactly. They are in the business of making their amplifiers look as good as they can. There's no way they are going to publish any numbers that paint their product in a poor light. Hence, the huge number of disclaimers, annotations and little numbers that lead to 'fine print'.



No way. Test the modules in accordance with established standards and report the results without fear or favor. Hypex have 'created' their own 'standards' and are holding them up as gospel. Headline advertised power- 700W@4R. Fine print continuous power "typically one fifth" but then they even derate that to 100W@4R.

Power bandwidth- 35KHz. Fine print power bandwidth testing limited to 5Khz @100W because the output caps will likely go up in smoke.

View attachment 39607



We all know that- several of us screamed it in the Benchmark review. But then again Hypex are the kings of low impedance, low gain, driven by a stupid low impedance source for their numbers aren't they? Hardly innocent eh?

What's good for the goose is also good for the gander it would seem, in this dodgy post-standards world.

John, the source impedance here is referring to driving the NC500 module stand alone. This is normally connected to the outside world through an input buffer.

The output Z of the buffer can easily be optimised for 40 ohms or lower. The input impedance of the buffer, what the outside world sees, is independent of this and can be designed for what Z you like, ie typically 10Kohms or above.

You have also been shown Hypex amps running full power FTC tests no problem, so why do you keep bringing it up?

Again what you fail to do is apply the context of the real world.

Can you show me a piece of music that will have content at full scale at 20kHz? Or even -40dB? If not then trying to make out its a big deal is extremely misleading.

Also you know full well real music RMS content is typically 1/5th of the peak so again in the real world this type of testing is meaningless.

If these are scenerios that never happen in real life why do you place so much importance upon them?

Call me defensive if you wish, but Im personally interested in tests that provide relevance to the real world.

This logic applies to all amps, not just class D

 

[ripvw]

ATI still makes class A/B amps - the Morris Kessler Signature AT4000 and AT6000:

https://www.ati-amp.com/AT4000.php

Perhaps it would be possible to compare one of their Hypex-sourced amps to a Signature amp and see if the huge difference in price is justified from a performance point of view. Perhaps restorer-john will finally get to see an amp made the "old-fashioned" way that lives up to his high standards. Given your positive review of the ATI here they may even consider sending you a couple of units for testing...

 

[restorer-john]

John, the input impedance here is referring to the NC500 module. This is connected to the outside world through an input buffer.

The input of the buffer can easily be optimised for 40 ohms output Z or lower. The input impedance of the buffer, what the outside world sees, is independent of this and can be designed for what Z you like.

Again what you fail to do is apply the context of the real world.

Can you show me a piece of music that will have content at full scale at 20kHz? Or even -40dB? If not then trying to make out its a big deal is extremely misleading.

Call me defensive if you wish, but Im personally interested in tests that provide relevance to the real world

The module is incomplete and it's performance will not get better through the addition of an external buffer. In fact, it will likely get worse than the specifications of the module as they stand in all but the very best implementations. (like yours). And yet, the incomplete specifications are held up as earth shatteringly good by all and sundry.

The real world requires amplifiers to be specified across the audible bandwidth for rated power and distortion.

I have asked you (nicely) to provide a full rated power 20Khz spectrogram, that's all. Can you do that? You have the amplifiers, the loads, the generator and the FFT. All you need is the attenuator network which I'm pretty sure you have.

Alternatively, send me one to play with- I promise I'll look after it.

 

[audimus]

This:

Or are you asking in general what noise shaping is?

I wasn’t familiar with this concept before, so I read the Wikipedia description. I sort of get the general idea but I thought it was based on moving noise well out of the audible range as your graph shows.

But then it was used in context of it being a possible explanation for increasing noise well in the audible range for the power to measure low for a given level of distortion. So, I was wondering if it was something else being talked about.

 

[March Audio]

The module is incomplete and it's performance will not get better through the addition of an external buffer. In fact, it will likely get worse than the specifications of the module as they stand in all but the very best implementations. (like yours). And yet, the incomplete specifications are held up as earth shatteringly good by all and sundry.

The real world requires amplifiers to be specified across the audible bandwidth for rated power and distortion.

I have asked you (nicely) to provide a full rated power 20Khz spectrogram, that's all. Can you do that? You have the amplifiers, the loads, the generator and the FFT. All you need is the attenuator network which I'm pretty sure you have.

Alternatively, send me one to play with- I promise I'll look after it.

The spec is for the module, it is not for a completed amp. We have Amirs testing of complete amps for that. You cant blame Hypex if others use the information out of context.

The real world does not require this, its actually misleading because it implies importance to some aspects which are simply not.

Sure, I will try and get round to it soon, its interesting info to have and I have no problem investigating it.

Just for info, further down that NC500 datasheet you will find the THD V Frequency plots. Here is 500 watts, so its quite capable of high power at high frequencies.

So it indicates there is something up with this ATI amp.

All Im saying is lets apply some context here so we can understand what is actually important instead of blindly looking at spec numbers.

 

[amirm]

Confusing to customers? So the pinnacle of audio science decides to withhold data because they don't want to confuse their clients. Or is it because the data completely sucks?

You really have that much trouble understanding what I wrote? No one has said Harman is pinnacle of audio science. We have said the research that was developed before, and advanced by the company is. The research. Not the company. The research. NOT THE COMPANY. Is it clear now?

And no, the data doesn't suck whatsoever. It would show their speakers to follow best research we know on speaker design. They also have such data on their competitors showing how terrible they are. Their engineering departments love to see this data released. But marketing says no. You could call their marketing department stupid or whatever, but don't conflate that into us, rest of harman, etc.

 

[amirm]

But people who buy based on group-think are destined to get what they deserve.

When I have a bacterial infection, my doctor prescribes antibiotics. You are considering that wrong and group think?

 

[amirm]

Well they say you are what you eat. So what does the king of audio have in his system? And how does it stack up against the best tested around here? And what was the total cost? The leader of a forum like this should have nothing but the best. And back it up as well.

I don't tell people to buy what I have. Unlike places you use to hang out, I am not out to show off my audio jewellery every chance I get to boost my ego. And/or brag about how much money I spend on audio gear.

But I do eat what I ascribe. I have Revel Salon 2 speakers. They are designed based on the best of audio science. They are expensive at retail price of US $22,000. I have them in an open space and combined with their low efficiency, they require tons of power. To that end, I feed them with Mark Levinson Class I amps that generate 1000 watts into 4 ohm. And I can tell you that I have come close to using all of that! Not for long, but I have. They cost $25,000 each. I also have a Reel to Reel Deck. An ancient Mark Levinson DAC which I plan to replace with Matrix Audio. A PC that drives them all. And room correction in the form of Dirac EQ. I don't recommend anyone duplicate my system other than Revel Salon 2 if they can afford it. The rest can be done with many other options at lower cost.

Now, tell us what you have. You can also give us your real name and what name you use on other forums so that we know your real character and whether we should believe anything you say.

 

[audimus]

Here is what I see as some inconsistencies in the treatment of this amp vs the general forum expectations and comments:

1. An amp that is not totally flat in FR but falls off a bit at the high end in the audible range is bad because the goal is total transparency and that is only achieved regardless of whether the slope at the extreme is audible or not or even if some people prefer it. We strive for that full bandwidth flatline perfection as an audiophile, not real world preferences. But this amp has very lower power at higher frequencies which would also have audible artifacts if it required more power but it is Ok because real world does not have content that requires more power in that range or as some have commented most people cannot hear in that range anyway.

You got to pick one or the other. Performance goal from a theoretical input across the entire audible range or performance goal which may measure bad in theory but ok based on real world inputs and hearing abilities to hear any such artifacts. One cannot pick and choose between the two based on what one is inclined towards.

2. The measurement of the Outlaw as an example

provoked unchallenged derision (referring to discussion comments here not the review) for supposedly audible imperfection for the roll off at the higher end.

This amp

so far hasn’t.

Which makes me think people aren’t really objective when it comes to interpreting data and suffer from every possible human bias to form opinions but consider themselves objective because it is based on “objective measurements”. A fallacy.

 

[Audiocrusader]

You really have that much trouble understanding what I wrote? No one has said Harman is pinnacle of audio science. We have said the research that was developed before, and advanced by the company is. The research. Not the company. The research. NOT THE COMPANY. Is it clear now?

And no, the data doesn't suck whatsoever. It would show their speakers to follow best research we know on speaker design. They also have such data on their competitors showing how terrible they are. Their engineering departments love to see this data released. But marketing says no. You could call their marketing department stupid or whatever, but don't conflate that into us, rest of harman, etc.

Isn't Mark Levinson what you run exclusively in your system? Now why would the world wide king of audio science choose to spend $70000+ on Mark Levinson gear in his personal system, when they refuse to even share measurement data with their clients? Isn't this just the type of manufacturers you spend every day of your life fighting? And at the same time you scream loud and clear to your followers that "It's the best there is!!" And you do this by owning it yourself. You could easily measure this gear in your personal system and share it with all your followers, but for some reason you don't. For me this is extremely questionable in what you real motives actually are. What are your real beliefs? The method I use to judge people is by watching what they do. Not what they say. Anyone can bullshit anyone. Especially on the internet.

And regarding Harman speakers. The reason they developed their own standards is so just like their electronics, they won't have to show the world that they actually suck by real standards. Cheap MDF boxes filled with crap generic crossover parts, low grade insulation. And for the Revel line since the don't have the chops internally, they outsource the drivers from SB Acoustics! They needed the Danish to design them because they must feel JBL doesn't have the chops! Pretty embarrassing!

 

[amirm]

Which makes me think people aren’t really objective when it comes to interpreting data and suffer from every possible human bias to form opinions but consider themselves objective because it is based on “objective measurements”. A fallacy.

The data is there for you to do with it as you please. My few words are there as far as thoughts I have at the moment about the measurements. I cannot in any form and fashion remember every review and try to be consistent to 0.1 dB in all of them. If you are unhappy with that, ignore the words and go by the graphs.

Really, you woke up this morning and thought worrying about flatness of the frequency response to 20 kHz instead of 0.5 dB would be the thing to fight about?

If you have another agenda, please take it out of review threads.

 

[March Audio]

Here is what I see as some inconsistencies in the treatment of this amp vs the general forum expectations and comments:

1. An amp that is not totally flat in FR but falls off a bit at the high end in the audible range is bad because the goal is total transparency and that is only achieved regardless of whether the slope at the extreme is audible or not or even if some people prefer it. We strive for that full bandwidth flatline perfection as an audiophile, not real world preferences. But this amp has very lower power at higher frequencies which would also have audible artifacts if it required more power but it is Ok because real world does not have content that requires more power in that range or as some have commented most people cannot hear in that range anyway.

You got to pick one or the other. Performance goal from a theoretical input across the entire audible range or performance goal which may measure bad in theory but ok based on real world inputs and hearing abilities to hear any such artifacts. One cannot pick and choose between the two based on what one is inclined towards.

2. The measurement of the Outlaw as an example

View attachment 39648
provoked unchallenged derision (referring to discussion comments here not the review) for supposedly audible imperfection for the roll off at the higher end.

This amp
View attachment 39649

so far hasn’t.

Which makes me think people aren’t really objective when it comes to interpreting data and suffer from every possible human bias to form opinions but consider themselves objective because it is based on “objective measurements”. A fallacy.

I agree we should be consistent.

However we cant ignore context and should not apply standards that are irrelevant.

In this particular amps case we note, as Amir has, the HF issue (It is not normal for NC500 based amps BTW), and then add technical context.

That is NOT applying non objective preference to the conclusions and its not a binary choice as you state.

We do the same with DAC tests. One might have 120dB SINAD and one might have 115dB SINAD. Will this cause a real world issue? Nope. Amir usually makes comment on technical anomalies and their potential subjective impact.

 

[amirm]

And regarding Harman speakers. The reason they developed their own standards is so just like their electronics, they won't have to show the world that they actually suck by real standards. Cheap MDF boxes filled with crap generic crossover parts, low grade insulation.

Harman speakers? What Harman speakers? There is no such thing. If you mean Harman Kardon, that is mass market stuff built to price to sell in big box stores. It has nothing to do with research or topics we discuss.

And for the Revel line since the don't have the chops internally, they outsource the drivers from SB Acoustics! They needed the Danish to design them because they must feel JBL doesn't have the chops! Pretty embarrassing!

Yeh right. You can be embarrassed while I enjoy listening to them!

Where is the list of your system? If that is not in your next post, I am going to ban you for two weeks for just picking fights, creating challenges you don't want to respond to. This would be your second warning and the third will boot you out.

 

[March Audio]

But people who buy based on group-think are destined to get what they deserve. I do care when established standards are eroded, specifications are incomplete or deceptive and performance doesn't measure up to the hype.

Even when those standards are unhelpful and even misleading?

 

[Audiocrusader]

So you ignore all of my questions because answering them would be devastating to your reputation. Is Revel not a Harman company? How many driver manufacturers does Harman own, and they couldn't build the Revel flagship drivers at one of them. They had to go to SB Acoustics in Indonesia for them. Because all they really know how to do is mass produce cheap MDF boxes in China. And blow smoke up everyones asses with marketing BS about science. And you take the bait hooklike and sinker. And at the same time claim to fight these types of companies. Very mixed messages here Amir.

And now since I'm right and you're wrong, I'm getting threatened to be booted if I don't share what my system is. Pretty mature Amir.

 

[audimus]

Really, you woke up this morning and thought worrying about flatness of the frequency response to 20 kHz instead of 0.5 dB would be the thing to fight about?

If you have another agenda, please take it out of review threads.

Let's not get personal please. We have higher standards here. - Amir November 5, 2019