NAD M23 VS NCore500 A/B test

[PaulHC]

Having finally been able to directly compare the M23 vs NCore500 though both have great test results - there is an audible difference.

I have one of the original hypex nc500 and hypex power supply as 2 monoblocks - i was able to do a switched listening test. The results were instantly audible - i thought the M23 sounded tight and compressed compared to the ncore - happy to go into more detail but in summary the main difference was the ncore sounded like it had the old fashioned "loudness" button pressed on meaning treble and bass more pronounced which gave a sense of detail and musicality - HOWEVER - back to back the M23 was MORE detailed with easily tighter bass and less shrill treble.

I agree we all hear different things (peaches and unicorns and rainbows were better etc) but this was a difference that was easily apparant on blind A/B testing - my very old ncore500 still great but not as good as M23 now ...

I wonder if its just the purifi module and the audiophonic would be the same as the m23 / c298 or is it both the purifi and new power supply that means i need to change power amps!

Need to hear that audiophonics ......

 

[VintageFlanker]

i was able to do a switched listening test [...]
but this was a difference that was easily apparant on blind A/B testing

You said "blind". But how did you level-match both? And who was switching?

 

[PaulHC]

"Blind" as i could get it as we switched a few times and in a few seconds at a good volume i could tell which was which - and i agree this isnt a scientific process and levelling occured with the volume remote and ears ! This isnt a sales pitch - but felt as a non believer in snake oil i should post that a slight amp cynic was disappointed how my origonal amp fared - not selling straight away but will probably look at nad after ive been to a chord amp demo ....... i entered comparison 95% confident you would not hear a difference i guess is my point !

 

[VintageFlanker]

"Blind" as i could get it as we switched a few times and in a few seconds at a good volume i could tell which was which - and i agree this isnt a scientific process and levelling occured with the volume remote and ears !

OK. So, neither scientific, nor even "valid" by any means, I regret.

i entered comparison 95% confident you would not hear a difference i guess is my point !

Well, confirmation bias doesn't work that way. You can't decide yourself if you're immune to it.

I'm not saying that there wasn't an actual difference... But that your "blind" test is barely a proof there was.

 

[Koeitje]

and levelling occured with the volume remote and ears !

So it was a 100% useless.

 

[thulle]

@PaulHC Welcome to the forums! I don't have a link unfortunately, but there's a ton of info here on how to do actual A/B-tests. I suggest reading up on it a bit or this will just be occasion number 57202 of a new person entering the forums and getting into an argument about testing methodology and biases we can't rid us of.

 

[PaulHC]

I understand guys and apologies - maybe should just have noted that i was surprised as a cynic there was albeit a possible perceived difference ! Its not my first rhodeo and im a great believer in no snake oil etc and was only trying to report on what surprised me for the first time in ages. Ive tested high end cables and with secret swapping was able to show no difference to well made inexpensive cables especially with digital transmission so enter all listening as a cynic. I remember the 50m of 24 awg bell wire vs 2 meters of 12awg "monster speaker cable" and yes i heard a difference ( a difference physics would predict ) so viva the debate !! Im on your side but welcome opinions from others.

What i really need is an opinion on whether the 1600 euro audiofonics purifi would sound "the same" scientifically as the more expensive M23 ...........

 

[MaxwellsEq]

What i really need is an opinion on whether the 1600 euro audiofonics purifi would sound "the same" scientifically as the more expensive M23 ...........

If accurately level matched, two amplifiers may sound different. But there would probably be measurable differences as well.

 

[PaulHC]

I agree and thats the purpose of this post now - to ask opinions with now a host of amplifiers producing amazing data on SNR / distortion / crosstalk etc etc etc does the inexpensive Topping PA5 sound the same as its rivals above and below it in the data tables ??? I havent the cash to buy a audiophonics, an m23, a topping pa5 and a benchmark ahb2 then sit back and review lol ! I have a nc500 and at least to my old ears it wasnt as good as a m23. Wanted to use opinions from forum to at least guide a "best bet " where to point the wallet at !

 

[Garlic]

What amp "brand" / "model" is your ncore 500 ?

The M23 is a pretty pricey amp, so it better sound good

 

[PaulHC]

Nord acoustics signature SE with sparkos op amps but one of the originals - at its initial build the power supply had real heat dissipation issues and the power supply itself needed capacitors lifted to avoid this. Its a remarkable amp that could compete with amps much more expensive in class A / AB but am wondering if purifi really now is, another step forward - but as my telling off above shows (lol) i have to insist it is up to the individual listener. What i hope from the forum is just informed opinions !

 

[VintageFlanker]

What i hope from the forum is just informed opinions !

Welcome, then. It all starts by stop believing in this kind of gimmick:

Its a remarkable amp that could compete with amps much more expensive in class A / AB

 

[Chrispy]

I agree and thats the purpose of this post now - to ask opinions with now a host of amplifiers producing amazing data on SNR / distortion / crosstalk etc etc etc does the inexpensive Topping PA5 sound the same as its rivals above and below it in the data tables ??? I havent the cash to buy a audiophonics, an m23, a topping pa5 and a benchmark ahb2 then sit back and review lol ! I have a nc500 and at least to my old ears it wasnt as good as a m23. Wanted to use opinions from forum to at least guide a "best bet " where to point the wallet at !

I think it more points out the poor comparison methodology. Then again I think it's largely a waste of time/effort to compare most modern amps in such a poor way.

 

[kemmler3D]

@PaulHC - first off, welcome to ASR! Second off, good work on actually testing your gear blind, even if the test wasn't ideal, you have the right attitude which puts you ahead of a lot of people who simply spend money without even seriously checking if it made any difference.

Since nobody has specifically said what was wrong with your test yet - your approach was right overall but missed some key details with regard to level matching. What you heard "as if the loudness button was pressed" is exactly the result you'd expect for identical amps if the level-matching was close, but not 100% matched.

I haven't done this myself, but if you ask anyone here or at DIYAudio (full of engineers and professionals, both) they will tell you the level matching needs to be done with a high-resolution voltmeter at the output terminals of the amp. You need to be within +/- 0.1dB for a "real" test, which is virtually impossible to do by ear. By ear, matching within +/-1dB would be a really good effort, but that's enough difference to make one amp sound better than the other, even if it's actually not.

The truth is there is basically no reason to expect any audible difference between any of these amps unless you drive them to heavy distortion. When people do measurements of them, they are basically identical down to 90+dB of dynamic range (at least) and up to hundreds of watts. If you claim to hear something that the measurement gear doesn't pick up, people are naturally beyond skeptical about it. In order to prove something like that, you need to follow very exacting standards for the test.

Anyway, again, good on ya for doing a test at all, and hopefully joining this forum is fun and informative!

PS I actually have some Nord NC500 monoblocks myself, I had to add fans to the cabinet I keep them in because they ran so hot! Maybe I have some of those early ones you're talking about... anyway, they are more than I need and I've never heard any noise or distortion from them. Subjectively I think they sound better than the Yamaha AVR I had them hooked up to before (which ran out of power at a pretty low volume), but my speakers are putting out vastly more THD than the amps ever will, and in all likelihood you're in the same boat...

 

[PaulHC]

Many thanks for such a helpful reply - my best support is a challenge i set which was a very expensive Mackintosh amp vs my humble inexpensive nc500 and i let the dealer decide ..... after a while he admitted the differences were very subtle ......... and that says it all.

 

[kemmler3D]

In general, decent amps won't affect the sound noticeably unless you run out of power. This is regardless of how much they cost - if they have flat frequency response, low noise, low distortion, and enough power, one is as good as the other. Most amps (that aren't absolute bargain basement cheapest-I-could-find-on-ali-express) fit these criteria, and although a lot of people want to believe otherwise, they cannot prove otherwise, because your NC500 is as good as basically anything out there within normal listening conditions.

What you should look for in an amp (or DAC, or preamp) is that it meets those basic criteria, and then look at features, warranty, serviceability, etc. Actual audible differences in performance are basically limited to speakers and EQ these days.

 

[Redwine]

In general, decent amps won't affect the sound noticeably unless you run out of power. This is regardless of how much they cost - if they have flat frequency response, low noise, low distortion, and enough power, one is as good as the other. Most amps (that aren't absolute bargain basement cheapest-I-could-find-on-ali-express) fit these criteria, and although a lot of people want to believe otherwise, they cannot prove otherwise, because your NC500 is as good as basically anything out there within normal listening conditions.

What you should look for in an amp (or DAC, or preamp) is that it meets those basic criteria, and then look at features, warranty, serviceability, etc. Actual audible differences in performance are basically limited to speakers and EQ these days.

So NC500 versus Purify designs don’t make a difference soundwise unless power is the limiting factor?

 

[kemmler3D]

So NC500 versus Purify designs don’t make a difference soundwise unless power is the limiting factor?

Realistically, in most listening situations, it would be almost or entirely impossible to hear the difference.

As I understand it, Amir's reviews are based on a theoretically maximal requirement for dynamic range. He aims at "is it even technically possible to hear noise and distortion from this amp?". This is what "audibly transparent" means in this context. So if you are playing a very clean 24-bit file and using the full dynamic range (i.e. peaks well over 100dB SPL) and you are also able to hear (at the same time) very small variations in distortion and SPL, and you have excellent listening skills, you MIGHT hear a difference between those amps.

In typical listening scenarios, the difference would be impossible to hear.

So, unless you need the extra power, the better SINAD is mostly a vanity metric, (higher numbers for their own sake), as they say in marketing.

I actually (somewhat, not enough to pay for it, though) share Amir's point of view, of wanting gear that is theoretically perfect. The idea that not only will you not notice any defects, but that it's NOT POSSIBLE to notice any defects, is appealing. As a practical matter though, this is like the difference between an IPX7 and IPX8 phone. Are you really going scuba diving with your smartphone in your hand??

 

[Deleted member 48726]

I get the the OP didn't do an approved A/B test but come on, folks. Let us focus on the actual question he asks and just acknowledge that he thinks a different is present. Know that you can be right but also know that you don't always need to let the world know that you are.

I think it's a good question I too think is interesting; what are the actual technical differences between the different d-amplifier using the same modules?

Is an nc500 module in a NAD just a pretty dress or have NAD made some technical choices that may change the sound?

 

[PaulHC]

I concur with your thread above and have several thoughts - first i do appreciate the conclusions of all that reproducible measurements cannot lie and snake oil is snake oil - however if u want to use cables as tone controls for example with EXTREMES of capacitance / resistance / inductance u will get measurable and I THINK audible differences in sound
At low listening levels i agree most amps will sound exactly the same
Where i think my perception of quality occurs is when amps are driven hard and i assume that is also a better more dynamic power supply which agrees with comments above (i think lol)

So back to the thread,
NAD build the purifi module under license so i presume it isnt modified but will check with NAD
I wonder if it was a better power supply in the NAD that at high volumes i perceived a difference - or am i, after over 45 years of hifi finally floating and hallucinating in a tub of snake oil ????