NAD M2

[nigel]

I was starting to research DACs and amplifiers to replace my venerable NAD 3020 amplifier (which I was connecting to the analogue out of my Airport Express) when I found out about the NAD M2, and listened to it at my local dealer. It sounds unbelievably great, and I love the technology, so I didn't hesitate to buy it.

 

It is essentially a top quality DAC, with a lossless volume control, that will directly power loudspeakers. It will supply 250W continuous into 8ohms, with more in reserve for transient peaks (like all NADs), so it should be happy with any speakers. All the processing and amplification is done in the digital domain, so that even the analogue inputs are first converted to digital. But it is obviously intended to work with digital inputs, and will accept up to 24bit/192KHz signals.

 

And it has excellent jitter rejection, so that I can feed it from my Apple Airport Express and there is absolutely no evidence of jitter in the sound that comes out of my speakers.

 

Please see the review at Stereophile for all the details and technical measurments.

 

http://stereophile.com/solidpoweramps/nad_m2_direct_digital_integrated_amplifier/

 

 

[simonholman]

Sounds like an excellent component. Seems like an Ultimate KISS solution. Also I noticed it has an AES XLR digital input so that it can take the CA's recommended Lynx sound card output via the HD26 to AES XLR connector cable. Will the NAD M2 accept 24/88.1 and/or 24/176.2 bitstreams?

 

[nigel]

Yes, it will accept both 24/88.1 and 24/176.2.

 

[simonholman]

Thanks. Actually I made a mistake; its 24/88.2 and 24/176.4, for what its worth.

 

Have you tried to use the built-in ADC and digital out to archive analog sources, ie vinyl?

 

[nigel]

No, I haven't tried this myself, because I no longer have any analog sources, but the user manual makes it clear that this is one of its intended uses. It explicitly confirms that, "This digital processor loop feature can be applied to all analog and digital audio input signal sources (Optical 1-2, Coax 1-2, AES/EBU, BALANCED and SINGLE-ENDED)."

 

And,

 

"DIGITAL AUDIO OPTICAL LOOP (OPTICAL LOOP OUT, OPTICAL LOOP IN): Connect OPTICAL LOOP OUT to the corresponding S/PDIF digital input of compatible devices such as CD recorders, receivers, computer soundcard or other digital processors."

 

[dallasjustice]

I have had the NAD M2 in my system for about 6 months. I also love it.

 

I use it for both 2 channel via my Lynx AES16 and surround via HDAV 1.3 deluxe to Parasound P7 (same computer). Sub integration is the only problem I have with it. It is really hard to find a single sub that will work well with Speaker Level inputs for the 2 channel listening and also handle the RCA or XLR sub input at the same time. Most sub manufacturers don't recommend this setup. I have talked to NAD about this and they just say that the M2 was designed just for 2 channel setups. I totally disagree, but thats what they say.

 

The sound is incredible. The M2 takes a lot of guesswork out of component/cable matching.

 

 

 

[nigel]

Great review of the NAD M2 by Robert Harley of The Absolute Sound, in their latest Guide to Integrated Amplifiers, which you can download here (PDF) http://bit.ly/9wFnEN.

 

He compares it favourably to his almost 10 times more expensive reference system, and also says:

 

"As for the M2 as an alternative to a $3500 conventional integrated amplifier and a $2500 digital-to-analog converter, it’s a slam dunk. I haven’t heard, nor can I imagine, any combination of amplification and DAC at the price approaching the M2’s performance. Moreover, the M2 delivers, in one chassis, decoding of high-resolution digital audio, the source-switching and control functions of a preamplifier, and 250W of amplification—all with outstanding ergonomics. I can envision the M2, or its descendents, as part of a three-piece playback-system: music server, M2-like product, and loudspeakers.

"NAD’s M2 is a triumph on many levels, not the least of which is that it points toward a new direction in amplifier design and system architecture. I predict that years from now audiophiles will look back on the M2 as the progenitor of the next generation of audio."

 

[ManWithAPlan]

This is an interesting device, and I have no doubt the sound quality is outstanding, i have much respect for NAD's higher end products like this. I just think it's so close, but still a miss! Why no ability to stream high quality audio files to it over a network? No network capabilities here at all. Why are folks so stuck with having their digital music files directly attached to a playback device? This is why networks exist. Store your files elsewhere on the network, across the house (in the basement??!!), wherever on the local home network. Then use a really great-sounding DAC that plays nice with high rez audio files, directly attached CD transports and other traditional "stereo equipment" sources, and can use a network the way the good lord intended. All this USB compatibility and driver concerns and windows/mac settings are all a total waste of time, that still result in one's "computer" having to be directly connected to the valued, precious living room/listening room stereo rack. In 5 years, you will never see this done again. The network music streaming reality is here, and has been for some time. Slimserver blazed a trail big time 7 years ago(though it had its high rez limitations), Olive made some great FLAC/WAV music servers as well at the same time (and still has a niche). These and many others have all been out there doing quite well for 7 years or more. Why would I want to move terabytes of high rez audio files back into the living room/listening room?! I guess this is why I own the PWD/Bridge from PS Audio. They totally get it, and are taking it to another level and doing it right by offering an integrated bridge into a high quality DAC with a nice remote control app. There will be others too, but why build out a setup that is dependent on directly attached USB/optical, coaxial, all of which have their limitations sonically, and provide more opportunity for loss in the chain, never mind the clunkiness of having a computer and file storage in the living/listening room.

 

Sorry, I know I sound like a fanboy, it's not the case. I still own and use my Olive Symphony, a very legacy product at this point, and still have use for the value of it, etc. I have evaluated and used many other products that thought they had it nailed. But if you're investing new dollars today in directly attached approaches, you are investing in yesterday's technology and putting yourself in a corner technology-wise when things change in the future. I truly do believe that PS Audio is on to something here that is truly paradigm changing, not the faux paradigm shift that Robert Harley talks about in his review of the M2. Mr. Harley, if you're out there, I have news for you - that "paradigm shift" of which you speak is almost 10 years old at this point. The true paradigm shift is simplicity, the old KISS approach. Use a network for what its good at, use a DAC for what it's good at, and put storage and noisy/heat generating disk nowhere near the living room/listening room! Give me a network interface to a high-end DAC, and let's use IP networks that we all have now to stream high rez music into our favorite listening room(s). If Slim Devices and Olive (not to mention DLink, Netgear and myriads of others) can basically achieve this in 2003 and 2004, there is no doubt that high end audio manufacturers can figure this out 7 years later, and do it way better and make good money at it.

 

I'm passionate because it frustrates me to see people spending net new dollars investing in an old paradigm with a limited future.

 

-Brian

 

[nigel]

I agree with you 100% about the need for hi-res networking interfaces into the audio rendering device. I stream my music from my computer room to my listening room using Apple's AirPlay into an Airport Express and then via optical to the NAD, but that is limited to 16bit/44.1kHz (which still sounds excellent to me), but I would prefer higher resolution directly into the NAD. The new AirPlay allows audio manufacturers to embed AirPlay networking into their devices, and it will be interesting to see what they come up with, but I'm not holding my breath for any increase above 16/44.1.

 

However, in the review, Harley is not talking about the "server to the DAC" part of the audio chain, he is talking about the "DAC to the loudspeakers" part of the system. It is in this area that the M2 represents a paradigm shift, in eliminating the traditional analogue pre- and power amplifiers, and all the noise and distortion that this analogue signal path adds to the music. Did you read the whole review, plus all the technical side-bars?

 

I'm confident that we'll see single devices incorporating both of these paradigm shifts in the next year or two.

 

[ManWithAPlan]

Nigel, yes i read the whole review, and I hear ya on the point about the DAC to the loudspeaker part of the chain. But that is hardly a paradigm shift really. Folks like Meridian have been combining DAC and preamp/amp direct to speakers for years, not to mention several others. I see your point, but calling this a paradigm shift, a new one, is a stretch.

 

You obviously can appreciate using network streaming because of your history with the Airport Express. It was revolutionary in its days in 2004, no doubt, and still does a nice job for folks - it just works. But the limitations of optical digital connections and the jitter issue, not to mention the 16bit/44.1 limitations, make for showstoppers these days. Airplay is very cool, and we agree that we are only at the beginning of seeing it embedded in all kinds of gear, video, audio, the whole shabang. But there is no need to wait, solutions exist right now.

 

My criticism on Mr. Harley is just that he never mentions an obvious missing piece of functionality in the M2 at all. He opines about every other matter under the sun, but doesn't opine at all that maybe a network capability would have made it more flexible, even suggest to NAD to add it later as a feature or add-on for consumers that they could charge for, etc. It's not vendor bashing which of course is verboden, but actual thought leadership, it is a consumer mag after all isn't it???

 

I expect folks with as much expertise, knowledge and influence in the industry as Mr. Harley to be thought leaders, not followers and vanilla reporters. He is more than up to the task and has the ear of audio manufacturers the world over.

 

Oh well...it is what it is.

 

That's all.

Brian

 

[dallasjustice]

I have a computer with SSDs, Jriver 15, Lynx AES16 and send bit perfect signal to the NAD M2. The sound is pretty amazing. I have no way of comparing it to other DAC+Amp combos, but i will say that the sound is awesome. I am sure that one could spend enough $$ to find a DAC+Amp combo that would sound better, but it would be much more expensive than $6,000 after you factor in expensive interconnects.

 

I am not in the asynchronous camp yet, although many of you are. The NAD M2 is not asynchronous. From what I have read from users such as "earflappin" and "happy", they have shown the beneficial use of an antelope isochrone DA AES/EBU regenerator between the AES16 and the DAC in a synchronous setup. I ordered one on Agon yesterday for $550, so I can report on that later on after RMAF. I am hoping for positive results.

 

I agree that the NAD M2 is not as revolutionary as described by TAS and Stereophile. I believe Lyngdorf has a similar integrated available. I have not heard it, but I am sure it is great. However, the NAD M2 is very special in that it is a DAC and amp all in one place and produces incredible sound. I would not say NAD's approach is outdated, it's just different. No one else has their technology; the Zetex chip behind the Direct Digital Feedback Amp concept. I will say though that I am glad that Stereophile and TAS at least have it on their respective recommended integrated amp lists.

 

 

 

I wish I could give you more technical information, but I am just a lawyer that can't add.

 

[MikeJazz]

I followed the same logic for a paradigm shift on my system - simplify, DAC with gain in one box..

 

I believe the Lyngdorf is still very competitive and I would suggest anyone willing to make this route to take a listen to both products.

 

Everyone seem to forget that Lyngdorf has similar functionality for many years now, so the M2 is not exactly so much of a revolution.

But yes, they know how to get media attention.

 

I second you both in underlining that networking capabilities should became more present in Stereo systems.

 

[bottlerocket]

Does this amp automatically switch to the incoming sample rate? I noticed there is a switch to set the sample rate. Is that for setting up-sampling or is it needed to manually match the incoming sample rate?

 

[MikeJazz]

I don't see any selectable sample rates in my TDAI2200.

The selection occurs in the CD player, I believe.

 

The manual states something else.

 

"The TDAI-2200 handles all conventional sample rates (192kHz, 176.4kHz, 96kHz, 88.2kHz,

48kHz and 44.1kHz).

To minimise jitter further, the sample rate of the input signal is

measured to determine the exact sample rate whereafter it is re-sampled to match the master

clock in the TDAI-2200 (although the input is stated at e.g. 96kHz it can easily ‘float’ slightly

both up and down)"

 

So its seems these folks are maniacs with precision...

 

From where I stand, I don't care at these details, but I care for the music...

 

[nigel]

Does this amp automatically switch to the incoming sample rate?

 

Yes, it automatically switches to the incoming sample rate of the selected digital input, up to 24bit/192kHz.

 

I noticed there is a switch to set the sample rate. Is that for setting up-sampling or is it needed to manually match the incoming sample rate?

 

Neither, the switch is to select the sample rate of the analog to digital converter that is used with the two legacy analog inputs. Analog inputs need to be converted to digital before they can be amplified by the NAD M2, as it works entirely in the digital domain.

 

Internally, the digital signals end up effectively oversampled to 35 bits and 108Mhz (yes, megahertz, not kilohertz). The internal 35 bit data paths allow the digital volume control 11 bits (equal to 66dB) of attenuation over even 24 bit inputs without loss of resolution.

 

 

 

[dallasjustice]

The NAD automatically switches to the digital input sample rate. The switch you are referring to only deals with analog inputs. Because it's a truly digital amp, it converts the analog into digital and then back to analog. Of course, you wouldn't be using the analog inputs for critical listening. IMO the analog inputs are only there to satisfy surround sound inputs so the amp can be used for both 2 channel via AES/EBU and front surrounds via analog inputs. That's the way I use it.

 

[Audio_ELF]

I maybe wrong, but I think isn't the NAD (close to) revolutionary in that the digital signal is directly fed into the power amp - something like the Meridian speakers or Lyndorf / Tact systems have a DAC converter buried amongst the electronics.

 

As for network interfaces ... I'm not yet convinced that a network interface approaches the flexibility of using a Mac or Windows computer - but thats for another debate!

 

Eloise

 

[nigel]

The NAD M2 amplifies the digital signal by converting the incoming PCM signal into a PWM (Pulse Width Modulation) signal at the internal clock freqency of 108MHz. Quoting from NAD's white paper about the M2:

 

"The actual amplification step is performed by the FET output stage, which amplifies the logic level pulses from the modulator output levels (3.3V) to high voltage pulses with amplitude of approximately +/-50V, and fed to the speaker terminals through an LC or reconstruction filter, which removes the high frequency energy and delivers the audio signal to the speaker. The output stage is where the very real challenges of switching power electronics arise.

 

"In reality, the pulses at the bridge output differ hugely from the perfect shape we might hope for, and the deviation from perfection results in errors in the output signal."

 

 

 

"To solve the problem, the Zetex team has developed an entirely new approach, which is best described as noise shaping error correction. Any deviation from the perfectly programmed pulse shape is regarded as an error. This could be caused by the amplitude of the pulse (power supply ripple or sag), the width of the pulse, or even the slope of the edges. Any of these factors will impact the area under the pulse (which is really how the signal amplitude is encoded).

 

"The system operates by comparing the output PWM signal with a high purity ‘Reference PWM’ signal to create an error signal, which is representative of the voltage error at the output. Integration in time provides an indication of the pulse area error, which is digitized at a conversion rate of 108MHz to pass back to the digital domain. The error information is then processed to compensate subsequent modulation cycles. The system can be considered to be constantly adapting to minimize the errors and hence deliver as true a signal as possible to the speaker."

 

 

 

If you turn the volume up on an M2 while playing nothing (or even while playing digital silence) and put your ear close to the speakers, you won't hear any noise at all, which demonstrates how successful this approach is. Music emerges from a true inky-black silence.

 

(You can download the full white paper here: http://nadelectronics.com/content/100218092123-M2-white-paper-EU-Web.pdf )

 

 

 

[bottlerocket]

I am interested in the Ayre integrated amp and the Ayre QB9 and the M2 is about the same price as the two Ayre components. I wonder how they compare.

 

[MikeJazz]

 

"If you turn the volume up on an M2 while playing nothing (or even while playing digital silence) and put your ear close to the speakers, you won't hear any noise at all, which demonstrates how successful this approach is. Music emerges from a true inky-black silence."

 

Hi Nigel, I have exactly the same experience with Lyngdorf TDAI2200.

Their volume control is amazing, completely silent!

 

[Codifus]

I've passed by this thread several times and wondered. Nigel, you upgraded your system from an Apple Airport Express feeding (via its well established and inferior analog outs) the venerable budget NAD3020 (costs about US $100.00 now) to using the same Airport Express but now using it's better digital output to feed your new NAD M2, a US $6000.00 amplifier?

 

That's a huge leap upwards:)

 

It's like one day I decide to trade in my 1960s VW Beetle for a $200,000 Rolls Royce:)

 

That being said I am mightily impressed by that M2. That device is the future of digital audio. With a 35 bit wide DSP section among other great attributes, it's so sexy that rotating that 24 bit volume control would turn me on:)

 

CD

 

 

[nigel]

I have exactly the same experience with Lyngdorf TDAI2200.

Their volume control is amazing, completely silent!

 

Awesome, isn't it?

 

 

[nigel]

Hi Codifus,

 

It's a long story, but I bought my NAD 3020 and KEF Coda III speakers in the early eighties, during my first job out of college. I also bought my first CD on March 1st 1982, the day they first came on the market in the UK. I couldn't afford a player at the time, as they were around £1,000 (about $2,000, which was literally 20% of my annual salary), but I bought the Marantz CD63 a few months later when it came down to around £400 (plus 5 free CDs!).

 

I enjoyed that system for 15 years, and it came with me when I moved from the UK to Florida, and then to California. In 1996 I bought a house with a living room pre-wired for surround sound, but because of the design of the room, there was nowhere good to put my stand-mounted KEFs, so I took the path of least resistance and installed a home theatre system, with small wall- and ceiling-mounted speakers plus centre on the TV set and subwoofer. I bought one of the first DVD players soon after, and one of the first receivers with Dolby Digital decoding (a Marantz, with the decoder being a separate unit from the main receiver). When I got a plasma HDTV with HDMI the Marantz was upgraded to a Denon with Audyssey, which greatly improved the sound in the room. With Blu-Ray, some movies, such as Avatar, sound amazing.

 

However, I had stopped listening to music on the home theatre system, because it never sounded as good as my NAD/KEF system. In particular, I stopped listening to classical recordings.

 

It was only this year when I finally found a good place in another room in my house to set up my stereo system that I rediscovered my old classical CDs, now ripped and stored in iTunes, together with a lot of new downloads. Technology has advanced a lot since 1982, and so has my salary, so I decided it was time for an upgrade.

 

My speakers are also about to take a huge leap upwards, as I will be taking delivery of a pair of Wilson Benesch Curves this weekend.

 

That's probably way more information than you wanted, but you did ask!

 

[Codifus]

.....is an enviable one, Nigel. And it's no wonder the home theater system suspended your love for music. My system is 2 channel only. I do have TV and play movies with it as well but my priority will always be the music.

 

A good read. Thanks.

 

CD