NAD M23 Stereo Amplifier Review

[pogo]

Why should they bother to build the board under license if not to add quality?

The 'in-house production' of the modules gives them a certain degree of flexibility with regards to matching with their custom designed input stage.
Additionally, they channel-match the left and right modules to be as close as possible. This helps reduce distortion in bridge mode also.

 

[mike70]

Because:

1 - there is pretty much no additional sound quality to be found. The Purify amps are already audibly transparent.
2 - Bruno's team are at the absolute pinnacle of this technology: They have been developing it for years. It is very unlikely that Nad has the technical capability to improve on it - or else why use it at all? If they could do better, they wouldn't have to buy it in.

we all know that is a rebranding ... at least, the Nad "packaging" didn´t make it worse than the original.
maybe you want the Nad logo in your living room, maybe a better support, maybe a better warranty, maybe ... whatever ... in the final result (the REAL result), the Nad implementation isn´t better and have 2x price tag.

Everyone have their decision, but never based on "Nad packaging is better", we have the measurements

 

[ahofer]

I think NAD needs to claim they made it better for the purposes of marking it up and superficially distinguishing it from, say, a Buckeye.

High end companies like to pose as the true innovators.

 

[mike70]

I think NAD needs to claim they made it better for the purposes of marking it up and superficially distinguishing it from, say, a Buckeye.

High end companies like to pose as the true innovators.

how to forget the Lexicon BD-30 fiasco? a Oppo player dressed with thick aluminum and all the jewelry for 3k :-(

https://www.audioholics.com/blu-ray-and-dvd-player-reviews/lexicon-bd-30-blu-ray-oppo-clone

Nad add the linear power supply, something that Bruno itself said is worthless in the Purify modules, and some "jewelry" to not be seen as Lexicon.

 

[MacCali]

By "demonstrations" I assume you mean sighted listening without matching levels, on varying speakers, in varying listening rooms?

Yea definitely, but it’s not for comparison. Just simply listening, experience what’s out there. I’m not here to compare. I’m just at my 5th year in audio and I like to see what’s out there.

I’m fairly fanatic, I have 3 stereo setups at home and two multi channel setups. At one point and still technically way to much, had 15 pairs of speakers just for stereo. And something to the tune of 40+ speakers when considering my multi channel.

And when I say tested I mean just like Amir’s reviews, using an analyzer

 

[Julf]

Yea definitely, but it’s not for comparison. Just simply listening, experience what’s out there. I’m not here to compare. I’m just at my 5th year in audio and I like to see what’s out there.

But what you experience is the speakers, listening room, your mood - pretty much everything except the amp.

 

[xaxxon]

And it probably and hopefully will have much longer and better parts support and service, plus it won't have a newer and "better" successor every half year making it losing its re-sale value drastically.

don't buy gear based on resale. But gear you like.

 

[xaxxon]

It's not cheap, and certainly not cheaply made. The purify design has been optimised primarily for sound quality over cost.



I doubt they have done anything at all to improve the sound quality. At most they might have made changes to adapt the mechanical design to suit their housing, or possibly integrated buffer stages to suit their input stage, or similar types of mod.



Some of this may or may not be true. But don't assume that because an amp is more expensive you are getting better components. Mostly what you are paying for in this case is branding.

Or at least designed to measure well. I wouldn't make assumptions about "sound quality"

 

[thewas]

don't buy gear based on resale. But gear you like.

I like equipment that lasts long and companies that have good service and support so no contradiction there.

 

[Leeken]

how to forget the Lexicon BD-30 fiasco? a Oppo player dressed with thick aluminum and all the jewelry for 3k :-(

https://www.audioholics.com/blu-ray-and-dvd-player-reviews/lexicon-bd-30-blu-ray-oppo-clone

Nad add the linear power supply, something that Bruno itself said is worthless in the Purify modules, and some "jewelry" to not be seen as Lexicon.

Maybe you could you link the esteemed members to pictures of the linear power supply Nad fitted?

Oh no you can’t,because they didn’t,this is a forum for facts not subjective imagination

They built they’re own smps,and they match the modules for bridging so there’s no magic smoke,simples.

 

[antcollinet]

Or at least designed to measure well. I wouldn't make assumptions about "sound quality"

I was making no assumptions.

 

[Bob101]

Or at least designed to measure well. I wouldn't make assumptions about "sound quality"

In Putzeys own words: Purifi Eigentakt modules were designed with maximum efficiency and flexibility as the primary objectives. A true fool-proof, powerful, affordable 'universal' power amp module for domestic use. The objectively excellent measured performanc (your thoughts on what that says about sound 'quality' may vary) somehow came with it... This is of course a somewhat simplified statement for the general public.

 

[xaqcraw4d]

Anyone have issues with reliability on the M23? I had my first one let the smoke out after 2 1/2 years. I was sent a new replacement, which just died after 9 months. NAD have effectively said "tough sh*t" and sent me to find a service center as I'm now 4 months out of warranty.

 

[fcracer]

Anyone have issues with reliability on the M23? I had my first one let the smoke out after 2 1/2 years. I was sent a new replacement, which just died after 9 months. NAD have effectively said "tough sh*t" and sent me to find a service center as I'm now 4 months out of warranty.

I’ve had my M33 since January 2021 and it’s still going strong, It’s your M23 + more electronics so if anything, it should be less reliable. My more than 20 year history with NAD has been favourable, however I noticed a trend. Whoever I sold my past NAD to killed it within two years. One pattern I deduced is that they placed the device where airflow was poor and my assumption is that things inside overheated. Any chance you’re placing the M23 in a cabinet or the like?

 

[xaqcraw4d]

I’ve had my M33 since January 2021 and it’s still going strong, It’s your M23 + more electronics so if anything, it should be less reliable. My more than 20 year history with NAD has been favourable, however I noticed a trend. Whoever I sold my past NAD to killed it within two years. One pattern I deduced is that they placed the device where airflow was poor and my assumption is that things inside overheated. Any chance you’re placing the M23 in a cabinet or the like?

They've both been in a cabinet but it has a fan system with thermostat to keep it under 85 F. Everything is powered through a Furman Ref unit. The amp is fed by an Anthem receiver and pushes a pair of Focal Aria 936s.

 

[fcracer]

They've both been in a cabinet but it has a fan system with thermostat to keep it under 85 F. Everything is powered through a Furman Ref unit. The amp is fed by an Anthem receiver and pushes a pair of Focal Aria 936s.

If you’re willing to continue with the M23, perhaps consider to keep it in free air or remove the power conditioner. Perhaps one of those is leading to the early demise. All my NAD have run either to straight AC or through a power bar, but never through a power conditioner. The M23 is a pretty simple amplifier inside, do you know what has smoked? Is it a Purifi module or the NAD power supply?

 

[xaqcraw4d]

If you’re willing to continue with the M23, perhaps consider to keep it in free air or remove the power conditioner. Perhaps one of those is leading to the early demise. All my NAD have run either to straight AC or through a power bar, but never through a power conditioner. The M23 is a pretty simple amplifier inside, do you know what has smoked? Is it a Purifi module or the NAD power supply?

I didn't open it up to see what went wrong, although it is rather tempting. I heard back from NAD and while they don't have stock to replace it ( I assume it's all the v2 now), they've agreed to cover a repair through one of their authorized shops. I'm not exactly holding my breath where longevity is concerned, but at least I won't have a very expensive boat anchor just yet.

 

[EPICURIOUS007]

This is a review and detailed measurements of the NAD M23 Class D stereo power amplifier. It is on kind loan from a member and costs US $3,749.
View attachment 291244
The M23 sports the nice look of other "Masters" series NAD product including substantial weight for a class D amplifier. The only miss is the touch button on top of the unit instead of the NAD logo. The touch sensitivity seems a lot better than previous NAD amplifiers though. Back panel shows the connections you expect:
View attachment 291245
The M23 is based on the Purifi amplifier which we know to be a high performance amplifier. NAD has differentiated itself by designing its own switchmode power supply. Let's see if that brings something to the party.

NAD M23 Amplifier Measurements
Let's start with our usual 4 ohm dashboard using XLR input:
View attachment 291246
We get slightly higher gain than reference design but that seems to have cost us a bit in noise, knocking down SINAD a couple of dBs. Strangely, we get that back partially by using RCA input:
View attachment 291247
Using an average of 102 dB SINAD, the M23 breaks into our top lowest noise+distortion amplifiers ever tested:
View attachment 291248

Noise performance is still excellent:
View attachment 291249
View attachment 291250

Frequency response is flat and load independent which is what we want to see:
View attachment 291251

Multitone test shows vanishingly low distortion:
View attachment 291252

New 19+20 kHz test runs at higher amplitude than Multitone so shows higher distortion spikes:
View attachment 291253

Crosstalk is extremely good:
View attachment 291254

Let's get into our power measurement and see if the custom power supply is doing us some good:
View attachment 291255
View attachment 291256
View attachment 291257

We definitely have more power than the reference which is a great thing. I also like the conservative and accurate power specifications.

Transfer function gets a bit uneven at higher frequencies but calms way down by 1 KHz:
View attachment 291260

The power supply seems to be juicing up the 20 Hz response.

So far our tests have been with resistive loads of 4 and 8 ohm. Let's add reactive (capacitive/inductive) load into the equation including going down to 2 ohms:
View attachment 291262

Wow, this thing is so load independent! I don't think I have tested an amplifier this good so far.

The amplifier is stable on power on:
View attachment 291264

Pop on is likely inaudible but you might hear something when you power it down (all done with the soft on/off control):
View attachment 291265

Couldn't figure out why the noise level was higher after I turned it off for the second time. Maybe it takes a while to drain down to nothing. It is not consequential though.

Conclusions
NAD shows how to take a standard design and make it its own with value added on enclosure, and custom power supply. The latter adds good bit more short term power to the amplifier which in my opinion is quite a bit more important than a bit of noise performance that is lost. You pay for this but remember the cost is that of the retail so margins are baked in for retailers.

I am happy to recommend the NAD M23 stereo amplifier. It is a job well done.
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may i ask what gain setting was this amp tested at?

 

[Mart68]

may i ask what gain setting was this amp tested at?

Dashboard at start of first post shows 29dB.

 

[EJ3]

High power amps are pointless unless you need to listen loud like with a PA system.

I think that listening is pointles if it is not loud. When it is loud, I can be doing anything in my home & listen to the background music (or even out in the yard).