NAD M33 Streaming Amplifier Review

[Vasr]

The second graphic is the list of companies (with the percentage of ownership) in the Lyngdorf family holding per official report.
(edit: and yes, there seems to be a few crosslinks - tracking that would require following the list of beneficiaries - available partly there, partly in other filings)

Thanks for the clarification. That makes sense. It is a list of subsidiaries of Lyngdorf. They own 23%-30% each of the two Purifi entities likely as founding shares (and seed capital) and has been funding their cash flow via debt. Doesn't look like Purifi itself has raised any equity capital. Not likely with approx US$200k yearly sales (assuming there aren't some zeros missing and approx $40k/year margins) and not much growth.

Don't think any of the principals are taking any salaries from the company (Total of approx $31k/year in salaries which doesn't go far).

Perhaps that explains the use of cheap caps.

But seriously, I don't see this sustainable for long as stand-alone without an acquisition or going into an IP licensing model or getting a mass-market vendor order (though not sure they can quickly scale to that).

So, whether NAD is actually taking the manufacturing off their hands is an important piece to judge its health. But they would need to get their modules into some high volume units than the niche/boutique plays they have been in so far. A licensing deal to one of the Japanese brands for a next gen AVR would be huge.

 

[watchnerd]

A licensing deal to one of the Japanese brands for a next gen AVR would be huge.

I thought most of the big Japanese firms had a "not invented here" mentality and preferred to make their own in-house tech.

Or maybe not so much anymore given they aren't the powerhouses they used to be?

 

[Matias]

NAD M33 was awarded Amplifier and Component of the Year 2020 on Stereophile. They reeeeally liked it.

 

[Odradek]

Hello, new member here! I have been reading for quite some time and had been eagerly waiting for this review.

Anyway, a question to m33 owners or orher knowledgeable members: I currently have my music files in my laptop, connected to an usb dac and then to my amp. I listen to music mostly like that, and watch the ocasional movie on a tv connected to the laptop via hdmi with the sound going through the usb dac. Is there any way I could use the m33 in a similar way?? I really dont know much about setting a network and dont know whether it could be a solution.

Auxiliary question: if there were an mdc module with hdmi in and out it could work, but would worse performance be expected? Same if there were one with usb input?

Appreciate any comments!

 

[Kal Rubinson]

There is an MDC module with USB in the works............................or so I have heard.
No promises, no dates.

 

[watchnerd]

There is an MDC module with USB in the works............................or so I have heard.
No promises, no dates.

What's the over / under on which comes first, USB MDC module or proper Roon support?

 

[Kal Rubinson]

What's the over / under on which comes first, USB MDC module or proper Roon support?

I have no idea.

 

[pogo]

Hello, new member here! I have been reading for quite some time and had been eagerly waiting for this review.

Anyway, a question to m33 owners or orher knowledgeable members: I currently have my music files in my laptop, connected to an usb dac and then to my amp. I listen to music mostly like that, and watch the ocasional movie on a tv connected to the laptop via hdmi with the sound going through the usb dac. Is there any way I could use the m33 in a similar way?? I really dont know much about setting a network and dont know whether it could be a solution.

Auxiliary question: if there were an mdc module with hdmi in and out it could work, but would worse performance be expected? Same if there were one with usb input?

Appreciate any comments!

An MDC module with USB will be available in the near future. This should also support the DSD format.

I use the old HDM1 module (Full HD) that is not yet recognized in my M33. Nad support is working on a problem solution. The newer HDM2 module (4K) seems to be running according to user reports.

My experience with the HDM1 module in my old Nad C388 was very positive. I had a Bluray player connected there with the option to only output audio via HDMI. I was able to play the following media up to a resolution of 192/24: Pure Audio Bluray, SACD (DSD -> 176.4K PCM), DVD-Audio, HDCD, CD, ...

I also had an Android stick connected for internet streaming services via HDMI.

 

[pogo]

Consider that you have an analog amplifier with a microcontroller monitoring it's behavior. In case an issue would be detected, the microcontroller will take drastic measures in order to protect both the amplifier, and the speakers. Not something slightly degrading the measurements, something like shutting down everything.

On register map location 0x07 you can read back Overcurrent Protection threshold which seems not to be hardwired and is probably given by the firmware. At least here the firmware seems to influence the audio signal in the threshold region.

 

[boXem]

On register map location 0x07 you can read back Overcurrent Protection threshold which seems not to be hardwired and is probably given by the firmware. At least here the firmware seems to influence the audio signal in the threshold region.

Edited
Fair enough. But we are talking about behavior at the limits, not at 5W.
No, the signal patch remains untouched. Page 20:

6.2 Overcurrent Protection (OCP)
Each amplifier channel is protected against short- and long-term high-current overload.
A system monitors the output stage current and abruptly engages a protection cycle (OCP cycle) if a pre-set overcurrent threshold is exceeded. During a protection cycle the power stage output is flipped, i.e., if the overcurrent event concerns the high-side FET the half-bridge output will be force low, and reversely, if the overcurrent event concerns the low-side FET the half-bridge will be forced high. The duration of a protection cycle is approximately ~300nS or until the output current has decreased below a safe threshold. The combined behavior of the OCP circuit is comparable to a current-limiter function.
Extended current-limiting can result in triggering of the Overload Protection (refer to section 6.3).
Following a protection cycle, normal operation is automatically resumed and no involvement from user or system host controller is required.
OCP is enable in all modes of operation (SW Mode, HW Mode).
OCP is reported in the I2C register (ICLIP) when operating in SW Mode.

 

[Odradek]

Thanks for your replies!

I imagine the measured performance with the usb module would at best be the same as in the review, or is it possible for example that jitter could be reduced?

 

[pogo]

Edited
Fair enough. But we are talking about behavior at the limits, not at 5W.
No, the signal patch remains untouched. Page 20:

Yes, we are talking about the behavior at the limits.

There is a first current limit function (OCP) with the threshold pre-set given by the firmware, which can cut slices of about 300ns, which can lead to an not clean audio output signal.

The OLP function mutes the audio signal output.

 

[Lorenzo74]

so this is the component of the year for Stereophile.

https://www.stereophile.com/content/stereophiles-products-2020-component-year

and I find important the following sentence:
At least as important for Stereophile and its readers is that it does all that with unassailable quality. Sure, there are people out there who will prefer the sound of their tube or class-A amplifier, but the amplification technology inside the M33—Purifi's Eigentakt—has the potential to win over even the most anachronistic audiophiles.

tubes and colored A class amplifiers are becoming the incumbent when class D is properly designed.

thanks in advance @Kal Rubinson for your much appreciated comment...

my Best
L.

 

[Vasr]

At least as important for Stereophile and its readers is that it does all that with unassailable quality. Sure, there are people out there who will prefer the sound of their tube or class-A amplifier, but the amplification technology inside the M33—Purifi's Eigentakt—has the potential to win over even the most anachronistic audiophiles.

I am not sure how a practically transparent amplifier is going to win over the Tube or Class-A amplifier audiophiles who like them precisely for their non-transparent qualities. Unless it comes with a Euphonics switch at the back...

Is Purifi Haagen-Daaz going to do what a Hypex nCore (or any competent contemporary Class D) couldn't do to convince those people? Is it because it tastes creamier than the others to appeal to them?

A relevant question is whether it will win over the supposedly "less anachronistic audiophiles" that moved on to Class AB for transparency. Will they notice a difference if they did a DBT including not reading Stereophile reviews first? So many questions....

 

[Kal Rubinson]

I am not sure how a practically transparent amplifier is going to win over the Tube or Class-A amplifier audiophiles who like them precisely for their non-transparent qualities.

I never said it would.

A relevant question is whether it will win over the supposedly "less anachronistic audiophiles" that moved on to Class AB for transparency.

Possibly but they will decide for themselves.

Will they notice a difference if they did a DBT including not reading Stereophile reviews first?

The M33 amp may be distinguishable. The point is that, even if it is indistinguishable, such an integrated product can be a viable option for many and not a compromise.

 

[Vasr]

I never said it would.

Splitting hairs are we?
Your article said

Sure, there are people out there who will prefer the sound of their tube or class-A amplifier but the amplification technology inside the M33—Purifi's Eigentakt—has the potential to win over even the most anachronistic audiophiles

I simply (and cynically) asked how that was going to happen given what they like in their sound.

The M33 amp may be distinguishable. The point is that, even if it is indistinguishable, such an integrated product can be a viable option for many and not a compromise.

I personally agree with a proposition that the allure of the single-box convenience (assuming the traditional tubeheads ever get into streaming) is sufficient to overcome any prejudices against Class D even if they hold their favorite amp to still sound better and thus like it even if grudgingly so. The cost factor is irrelevant for such crowds anyway.

I also think such a value proposition would be satisfied with any decent nCore amp module with similar integration. I just don't buy into the prevalent hype (not referring to your writing here) that Purifi E is somehow such a game-changer that it would convert such "anachronistic audiophiles" from the amp quality.

For me, the switch to Class D was a very practical one - less heat, smaller form factor and no noticeable sound quality difference from previously owned technologies (except as may manifest from power differences). I doubt I would be able to make out the sound quality difference between various generations of Class D over the last few years (even if there were measurable differences). I doubt most would.

Did Stereophile ever consider or do DBT tests in their entire history? I cannot recall but may have missed it over the decades.

 

[Kal Rubinson]

I simply (and cynically) asked how that was going to happen given what they like in their sound.

Now, who's splitting hairs?

Did Stereophile ever consider or do DBT tests in their entire history? I cannot recall but may have missed it over the decades.

Yup. Before my time.

 

[Lorenzo74]

This has been already posted in ASR, however it is very interesting reading especially if we consider it has been written 35 years ago.
https://www.stereophile.com/content/carver-challenge

what if someone will come out with a “small dsp board“ to retrofit (front fit) latest class D Amps with the flavour of multithousands tube or even ACA AB amplifiers?

I’m always puzzled how intensively in many forums analog (anachronistic) Audiophiles strive for quality investing thousands of €-$ even in power cables while opposing any DSP, EQ, MQA, streaming devices, praising the superior quality of their piece of art, heavy weight, fascinating, super complex turntables....

it’s the epitome of the oxymorons!

 

[pogo]

I am not sure how a practically transparent amplifier is going to win over the Tube or Class-A amplifier audiophiles who like them precisely for their non-transparent qualities. Unless it comes with a Euphonics switch at the back...

Is Purifi Haagen-Daaz going to do what a Hypex nCore (or any competent contemporary Class D) couldn't do to convince those people? Is it because it tastes creamier than the others to appeal to them?

A relevant question is whether it will win over the supposedly "less anachronistic audiophiles" that moved on to Class AB for transparency. Will they notice a difference if they did a DBT including not reading Stereophile reviews first? So many questions....

The M33 platform has the potential to emulate a tube amplifier sound, among other things. But I cannot imagine that something like this will be implemented. I rather hope for a DIRAC for headphones.
I also admit that I belong to the apparently rare genre that can hear clear differences between the different amplifier technologies, for example a Nad C388, M10 and M33.
I can only recommend anyone who has the opportunity to hear this amplifier live.
'It's Simply a Matter of Time' seems to play an important role in the entire signal path.

 

[Alexanderc]

Wow, these are still out of stock at all the major online retailers in the US. Crutchfield's site says they'll be back in stock in March! I guess no discounts likely for a while