NAD Masters Series M51
Stereo DAC/digital preamp (Silver)
Item #: 745M51
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Item #: 745M51
Your price: $1,999.99 Earn up to 2,000 Rewards points
Sure, NAD's M51 is an exceptionally musical-sounding digital-to-analog converter, but it's much more than that. It's also a versatile digital preamp with enough inputs to handle all of your digital music sources: disc players, network music players, and even your computer. What puts this DAC in a class by itself is NAD's acclaimed Direct Digital technology, which uses immense processing power to transform digital bits into music that's warm, involving, and lifelike.
NAD's powerful processing engine has exceptional speed and accuracy compared to typical DACs. To get technical for just a moment, the M51 re-samples the incoming pulse code modulated (PCM) signal and converts it to a pulse width modulated signal (PWM) with a sampling rate of 844kHz. One big benefit of converting PCM to PWM is that it completely eliminates any timing errors, known as "jitter," in the incoming signal. That's reflected in the M51's vanishingly low numbers for noise and distortion.
Specifications matter, but they can't describe the energy, presence, and life that the M51 restores to your music. Thanks to this DAC's extremely high clock speed, sophisticated filters can be used to remove nasty digital artifacts like ringing, while maintaining the nuanced dynamics and tonal purity that will make even familiar recordings sound fresh.
The M51 offers an array of digital inputs, plus high-quality analog outputs including balanced XLR.
The M51 is uniquely equipped to dramatically improve the sound quality of all your stereo digital music sources. It has a coaxial digital input, which is great for connecting a CD or DVD player, or a Sonos® Connect player. And an optical digital input is the ideal hookup for your HDTV, Apple TV®, or game console. In addition to these common inputs there's an uncommon balanced digital XLR input that provides an ultra-low-noise connection when used with a compatible high-end CD transport.
A Type B USB port makes it easy to feed the output from your computer into the M51's superb DAC, bypassing your computer's sound card to yield much higher quality sound with stored or streaming music files, including high-res files with sample rates up to 192kHz. (Free USB driver download required for Windows® PC playback.)
Plus, the M51 is the first unit of its kind that we've seen to offer HDMI connections: two inputs and one output with video pass-through. This gives you access to the high-quality 2-channel soundtracks found on nearly all Blu-rays and DVDs. Many symphony orchestras and some specialty music labels are also releasing high-res audio recordings on Blu-ray or DVD.
Praise for the NAD M51 from Stereophile
"The M51 projected a rich, lovely sound that wasn't too forgiving, which was to its credit. I like to hear a recording's technical warts, if any."
"I prefer DACs that reveal as much as possible about what was captured on the tape or in the digits, and couldn't care less about adding a rose-colored tint to dodgy digital sound. In this regard, the NAD M51 succeeds with a wonderfully detailed and revealing sound best described as honest, with a friendly smile. And it was a pleasure to listen to. "
— From Jon Iverson's review in Stereophile, July 6, 2012
Read the full review
The M51 is a fully functional digital preamp with one of the world's best volume controls. NAD's 35-bit architecture makes it possible to have a DSP-based volume control that does not reduce resolution — even with 24-bit high resolution signals. In fact, all switching and volume control is done in the digital domain. The only analog circuit is the Class A buffer at the output of the DAC.
Note: input selection is available from the front panel, but volume can only be adjusted via the remote control.
Why buy a separate DAC? These devices are all about getting true high-fidelity sound from digital sources like computers, streaming music players, smartphones, and more. While these kinds of sources usually have their own digital-to-analog converters built in, you can expect a separate DAC to give you much better accuracy and finer detail.
I was sold on this DAC when I heard how much better ordinary, red-label CDs sounded. Singers' breaths, for example, come across with startling presence, adding a live element that was never there before. Then I began playing hi-res music--wow! The best fidelity I have ever heard--expanded frequency response on both ends, the blackest backgrounds, explosive dynamics, a truly immersive experience. With the addition of a headless music server controlled by an iPad, I am enjoying better sound and convenience than I have ever known. I now realize that without this DAC I would never have known what my carefully curated system was capable of.
I also like the adjustable dimming of the display and the fact that the remote controls the volume--especially helpful since my tube-hybrid pre-amp does not have remote control. I agree that the remote needs a light and that the lettering on the source buttons is too small and dark to read easily. But overall this DAC has contributed significantly to my enjoyment of music. The price isn't cheap, but with the prices of truly high-end audio and the quality of this thing's sound, this DAC is a bargain.
Pros: Immersive sound. Optical, USB, Coax hook-ups give flexibility. Remote control volume adjustment (I would never use a control on the unit anyway).
Cons: Remote needs a light and source buttons that are readable.
Replaced a Peachtree Grand Pre with this after also comparing with the Benchmark DAC2 HGC. The listening test was spread over 10 days after allowing the Benchmark to 'burn-in' for a week. The Benchmark felt very precise and clinical in sound and presentation. The Peachtree sounded very similar, though brighter. The NAD just seemed much more open and natural sounding, with a better sense of timing. The result on my system was that the soundstage seemed to hang in the air in front of the speakers a lot more with the NAD than with the other two. The NAD also made streamed music from Spotify sound better than the other two. This includes the Peachtree's tube buffer which is meant to smooth out harshness. Horn sections sounded better to me on the NAD, with sense of being there in the room.
In general, several positive reviews you can find on the web about the NAD and comparisons to similarly priced units like the DAC2 HGC ring true for me.
When it comes to build quality, the Peachtree is absolutely the best. It looks and feels like a premium component, the NAD next and then the Benchmark.
Test equipment: Source: Oppo BDP-105, Mac Mini running Pure Music 1.x, SONOS Connect, Apple TV DAC/Preamp (Comparison: Peachtree Grand Pre, Benchmark DAC2 HGC, NAD M51 Classe CA-2100 Stereo Power Amp Paradigm Reference Studio 20 v5 Veldoyne DD+ 10 Media: 16/44.1, 24/48, 24/96, 24/192 files on Mac Mini, Spotify through SONOS, CD via Oppo
Pros: Sound Quality, Timing, Sense of Realism and being there, revealing, organic/natural, HDMI input opens up new possibilities
Cons: Lack of volume buttons on the Device. Boot Up time is very slow compared to all the other devices and therefore, when used with a universal remote like Harmony, it's tough to use automated activities that also switch the input on the NAD as part of the macro. I added a soft button for the right input for each activity, so that I can set it after boot up is complete.
As a 20 year fan of Wadia, I was skeptical anyone would meet or exceed their digital volume control. This NAD does, and at a reasonable cost and superior simplicity of use. Great device.
Pros: Simplicity of use.
Cons: Remote too general. No ability to control when it goes to "sleep" - results in requiring the NAD be powered on from remote when you also start up your playing device.
The reviews from the various sources are spot on about this unit as far as the sound is concerned. The Benchmark DAC HDR was my first outboard DAC and I really enjoyed it but went to the NAD out of curiosity and because I did like the fact that it can act as a receiver of sorts i.e. wife can handle it better and it accepts HDMI with video pass-through, and because her and I watch more streaming tv on the 2.0 system I have than HT setup i.e. the up-scaling is excellent with ROKU 3 video/audio streaming. I love the fact that I can see the sampling speed on the face because it identified a problem that I haven't noticed--my computer wasn't outputting music properly, however, I had a benchmark HDR which isn't comparable to the M51 i.e. the DAC2 does have sampling indication. The sound is spot on with what professional reviewers have said e.g. warm, fun to listen to, full, etc. I have enjoyed it and was looking for a more relaxing sound than the Benchmark, However, I do think the comparison is apples and oranges. I will be attempting to fuse the benchmark and NAD qualities with silver inter-connects, but if that doesn't succeed I will still keep the NAD. Ultimately, the M51 is a unit that has very easy functionality, excellent sound that is very rich, and is aesthetically pleasing and functionally compatible with my other components.
Pros: Excellent sound, great for up-scaling media, great functionality.
Cons: No "cons", just trade-offs.
Moved up to this unit from a DacMagic100. The clarity and balance is amazing from top to bottom. Complicated passages feel untangled.
Pros: Amazing clarity
Cons: No front panel volume control if used as a preamp.
Spectacular clarity. Clean, explosive dynamics. No need for a pre-amp. These are wired into two big Bryston 7BST mono blocks (balanced) and there is ZERO noise. I can pause a music track, turn the M51 up all the way, put my ear to the speaker and hear-- nothing. This level of silence creates a noise floor where every nuance is discernible. I have owned many high-end audiophile grade products, and I'm surprised this doesn't cost over $10k.
Pros: Clarity. Noise Floor. Dynamics.
Cons: Lack of volume control on the unit.
It's early but this piece sounds terrific and offers excellent connectivity and functionality for my 2.1 system. I wish the remote was a little more user friendly and a volume switch would be nice but you can't have everything.
Almost can't believe the difference this unit has brought to all of my digital audio, CD's, internet radio, computer, any digital source all into another realm of sonic bliss. Pandora radio has such a huge sound stage now. Worth every penny at this price. Sounds nearly like vinyl on an expensive turn table.
Pros: Instant improvement to any digital source. A real bargain for the price.
Cons: Can't think of any.
This DAC replaced the Oppo BDP 105 in my computer based stereo system. The improvement over the high quality 2 channel DAC in the Oppo was immediately apparent. Most generally, it had a liveliness to it that I was missing in the Oppo. Sound was also fuller. Just more engaging with a variety of music from a variety of sources. Noteworthy for me was how much better streaming services like Spotify Premium and MOG sounded. That's special. These lower resolution sources sound worse in some high-end systems. As for high resolution sources, my studio master quality download of Berlioz Symphonie Fantastique by Robin Ticciati and the Scottish Chamber Orchestra was a revelation. Finally I heard what I had been hoping for. The beauty of this level of music playback is really something! My present system uses JRiver Media Center and JPlay software on a Windows 7 pc. Speakers are Dynaudio Focus 110A (active monitors). Have to confess that there is one additional ingredient that makes a big difference: an iFi iUSB Power device that simply slips between the computer and the DAC on a usb cable and cleans up the power coming through the usb connection. A bit geeky, but it works for me.
Pros: One of the best DACs on the market at this price with a proven track record of very satisfied users. Display has great visibility. Remote works great for me, and you don't need to use it often except to adjust volume ( there is also an option to lock the volume and adjust it through another component).
Cons: none really. One can always want different features, but this gets the essentials right.
Great Sounding DAC. All the reviews about the sound are right on. Really great, and works well with Sonos and streamed content, although the best sound came from streaming from my MAC through USB (with the automatically upsampling codec apparently employed by NAD but documented nowhere). I love it and will likely be keeping it, but I do have some nits to pick that I interpret as lack of thoughtful consideration for users,. I presume only audio obsessives buy such things, so documentation is actually interesting to us (me). There is a manual (on a CD), but it says essentially nothing except explain the remote. The remote has not light, and the sources are labelled in tiny letters that are difficult to read, and has a ton of buttons that are only for other NAD components. Give me a small one that is relevant to me. No volume button on the unit, only through crappy remote. And lastly, 5 brightness levels for the display but none to turn the display off.
Pros: Sound is Beautiful! (although I am suspicious that, with all of the upsampling and undocumented magic going on within the unit, how software upsampling via USB, of CD quality output sounds so different from direct, unmolested CD quality digital coax that is only using the DAC. I wouldn't think that pre-upsampling would improve the sound from a DAC that does so much internally, but it clearly does. Which makes me wonder.... HDMI video passthrough is GENIUS! Hello Jools Holland!
Cons: No display off. Remote. Documentation. No Volume control on unti, only from remote. plug and play, no options (I like to play a little, read, and understand ). Only one digital Coax input.
Like many others, I've been transitioning over to streaming music - has been a hard sell for me, though, because of quality vs. convenience factors. (My main system is NAD T787 AVR, Marantz NA7004 NW Player, NAD C565 CD, Oppo 93 BR, PSB Synchrony Speakers, 5.2 setup). I've been running Airplay in 3 rooms + patio for a few years, basically as background music, using Apple Lossless files. I've dabbled a bit ripping some of my 450+ CDs to 16/44.1 FLAC via dbpoweramp, downloaded some 24/96 HDTRACKS, mostly just experimenting. Figured that if I could get streamed music to be almost as good as direct play, I'd take advantage of the convenience.
The internal DACs in the T787, C565 and NA7004 are all "pretty good", but I found myself constantly switching/upgrading cables, back & forth between analog & digital from some components, etc. Always trying to eek out a bit more from my systems, I tried out various dealer demo external DACs at home. The clear winner in the "up to $2000" range is this NAD M51, hands down. So I got one. Strongest points: clarity, separation, bass definition, and overall soundstage -- from any connected source, including streaming ALAC via Airplay or FLAC via DLNA, and direct CD. Now I've got the streaming quality I was looking for.
I'm still not sure exactly where I'm going next with the streaming bit, e.g., dedicated laptop, NAS, larger downloaded HD library, or just finish the FLAC rips for now -- but with this DAC I know I'll be ready!!
Pros: Sound Quality is amazing. Clarity, separation, soundstage, tight bass. My Synchrony towers seem like they're each about 4 feet wide, a true "wall of sound"! And my PSB 300 subs have NEVER sounded so musical.
Cons: Not really a con, but note that the M51 takes a LONG time to break in fully, took me several weeks of nearly constant play before harsh highs and boomy bass went away. Biggest gripe: I would have liked a couple more Coax & Optical inputs, had to reroute a few components thru the Marantz NW player instead of direct to the DAC. Eventually this will sort itself out, when mostly using streaming, but annoying for those in transition.
This is a great sounding dac and for the money it should be. I got this dac to decode 24/192 stereo audio tracks found on some Blu-Ray discs and some DVD-A discs. There are also some 24/192 downloadable music files out there that can be sent to this dac via a computer or player like the Oppo 95. Make no mistake, this is a stereo dac. There really aren't any 5.1 or 7.1 stand alone dacs out there that I am aware of. This is the only HDMI input dac that I am aware of that is not some black box kludge made for hobbyists or "pro" audio. With some BD and DVD/DVD-A discs, the only way you will be able to listen to the high resolution stereo tracks other than via an AV receiver or the in board dac in your player (like the Oppo 95), is to send the signal via HDMI cable to a dac like this. 24/192 source material thru this dac sounds PHENOMENAL. SACD for the most part sounds better than CD. DVD-A at 24/96 generally sounds better than SACD. 24/192 audio sounds better than 24/96 audio and it's not subtle at all, like a sledgehammer is not subtle. The classical music cognoscente have known how good Blu-ray audio only discs sound for some time. With the m51 they sound even better. Pity this thing is not 5.1 or 7.1 channel capable and then you would really have something, a true 5 star product. As it is, it is an incredible sounding dac albeit in stereo. Still comparing it to an old $6000 Mark Levinson dac w/24/96 audio. The same music via this dac 24/192, no comparison.
Pros: HDMI in and out. Incredible sound.
Cons: Stereo only
Outstanding DAC. It manages the holy grail in DACs---incredible detail with musicality and no digital glare/harshness. I auditioned 6 dacs before choosing this one. Base is tight, clean, nuanced and with a power and depth that is amazing. Imaging is excellent and wide. Instruments and voices seem to come alive and make you feel like the musicians are playing in your room. You will be able to make out the words in the music that you might not have been able to understand before. Its not cheap, but if you can afford it, then its a real no-brainer, slam dunk. NOTE: make sure you send this DAC a low jitter digital input signal, because, like nearly all good DACs, it doesn't add any of its own jitter but it doesn't perfectly reject jitter from incoming sources. Also, make sure you send the output of this DAC to a high quality linear power amplifier that has good synergy with your speakers.
Pros: outstanding bass, excellent imaging, instruments and voices seem to come alive.
Cons: perhaps price-- but they don't have competition at this performance level for this price
Direct Digital DAC/Preamp: The NAD M51 Direct Digital DAC introduces many "firsts" for the DAC product category: first to support HDMI, first to support USB Audio Class 2 with support for 192kHz, the first to use digital error correction, and the first 35-bit architecture to be found in a DAC. The M51 is also a fully functional digital preamp with seven digital inputs and one of the world's best volume controls. As a "preamp" it is totally noise and distortion free, because all switching and volume control is done in the digital domain. There are no analog circuits except for the Class A buffer at the output of the DAC. Whether you want to get into computer audio, Home Cinema 2.0, or just want to upgrade your CD player; the M51 Direct Digital DAC will get the best possible performance from your digital formats. All this innovation, performance, and flexibility come with NAD's legendary sound quality and performance.
Direct Digital Technology: NAD's Direct Digital technology is unique in both its extreme precision and in its speed. Direct Digital technology uses a very powerful processing engine that operates at much higher speed and with much greater accuracy than typical Digital-to-Analog converters. Running at 108MHz, the M51 resamples the incoming pulse code modulated (PCM) signal and converts it to a pulse width modulation signal (PWM) with a sampling rate of 844kHz. Operating in a differential mode with double precision, the M51 has state-of-the-art specifications for low noise and distortion free sound. The extreme headroom afforded by the 35-bit architecture allows for a DSP-based volume control that does not reduce resolution. Even with 24-bit high definition signals, the output can be attenuated by 66dB (very quiet) before bit truncation begins.Precision Processing Engine: The incredible precision of the M51's processing engine gives music a vibrancy and transient accuracy that must be heard to be appreciated. The conversion process from PCM to PWM completely eliminates any jitter present on the incoming signal; again, offering state-of-the-art performance in this most important parameter. Due to the very high clock speed and mathematical precision of our reconstruction filters, the resulting audio signal is totally free of digital artifacts like ringing.
Pure Class A Analog Stage: A Pure Class A analog stage with very low output impedance provides the perfect interface to your favorite amplifier. Also, both balanced (XLR) and unbalanced (RCA) outputs are available.
Power On/Off Switch: The NAD M51 direct digital DAC's main power switch is located on the rear-panel. Once this main power switch is set to "On", you can switch the NAD M51 from "On" to "Standby" using the front-panel On/Off button.
Input Selection: There is an Input Selection button on the M51's front-panel which allows you to switch between connected sources (AES/EBU, Coaxial, Optical, USB, HDMI, & HDMI2).
Remote Control: The supplied IR remote provides wireless operation of the M51 and features controls for NAD's matching M50 Digital Music Player (745M50, sold separately).
USB (Type-B) Port: The NAD M51 direct digital DAC is ready for the world of computer audio with its rear-panel asynchronous USB (type-B) input that can directly stream 24-bit/192kHz content from your Windows PC, Mac computer, or other network-attached storage device (NAS). Your computer will need to meet the following system requirements.
Note: Download the "NAD USB 2.0 Audio Driver" and install this driver to your Windows computer. Mac OS X Snow Leopard (version 10.6) and later versions already include USB Audio 2.0 drivers (no need to download NAD USB 2.0 Audio Driver).
Digital Audio Inputs: The NAD M51 Direct Digital DAC includes three digital audio inputs; optical (Toslink), one coaxial (RCA), and one AES/EBU (balanced XLR).
Note: If connecting to a television set's optical output, please make sure that you are able to select PCM as the default optical out audio format from your television's Audio menu. This DAC is not compatible with multi-channel audio signals and will not work with televisions that do not output PCM.
Analog Audio Outputs: The NAD M51 offers balanced (XLR) and unbalanced (RCA) analog audio outputs.
HDMI Inputs/Output: The M51 offers two HDMI v1.4 inputs and one HDMI v1.4 output with video pass-through. This opens up the possibility of using the M51 Direct Digital DAC as the heart of a "Video 2.0" system using the mandatory two-channel linear PCM soundtrack from Blu-ray or DVD to make a compelling two-channel high definition theater presentation. Many symphony orchestras and some specialty music labels are also released in HD recordings on Blu-ray or DVD. The M51 is fully 3D video compatible, but there is no surround sound decoding or video processing.
USB (Type-A) Port: The M51's USB (type-A) port is only used to update the unit with future software/firmware upgrades from NAD.
12V Trigger Inputs: With this 3.5mm input triggered by a 12V DC supply, the M51 can be switched On remotely from standby mode by compatible devices; such as amplifiers, preamplifiers, receivers, etc. If the 12V DC supply is cut off, the M51 will return to standby mode.
IR Input: This 3.5mm input is connected to the output of an IR (infrared) repeater (Xantech or similar) or the IR output of another component to allow control of the M51 from a remote location.
RS-232 Port: The RS-232 port allows connection to a compatible PC or external whole-house control system from companies such as AMX or Crestron. NAD is a certified partner of AMX and Crestron and fully supports these external devices.
AC Power Cord: The M5 comes supplied with a detachable 6' AC power cord.
Not that I know of But you can control pro amps with iPad iPhone apps I have crown xti2 amps and this method works very well Set the dac to your liking and control the rest with the software in the amps Hope this helps [ William Sep 28, 2015 ]
I use the Roomie IR blaster, app, and subscription service which syncs with all my old iPhones. Tip: if you are not good figuring out new stuff find an audio pro or techie to get it programmed for you. Then on every phone you have is a backlit, touchscreen remote. [ Bart Sep 28, 2015 ]
Not that I know. [ James Sep 28, 2015 ]
Hey Los I have not used the unbalanced connects so I sorry I can't help My setup is balanced to Crown XTI 2 amps that are daisy chained I can tell you this, the Nad DAC is a quality product and sounds great hooked up through USB if that's your intended use. Zero hum through balanced. Shoot an email to NAD and ask them [ William May 27, 2015 ]
Both are active at the same time and I've used it in a similar configuration (driving two separate amplifiers) with no ill effects. [ Aaron May 27, 2015 ]
Yes, they will have simultaneous output. I have the balanced outs connected to my loudspeaker amp and the unbalanced outs connected to my headphone amp - usually only one of those has power at any given time, but I just tested & confirmed there's output to both at the same time. [ Steven May 27, 2015 ]
Yes. Both the balanced and unbalanced outputs send signal simultaneously. [ david May 27, 2015 ]
Yes, but of course the gain levels are different. [ JARED May 27, 2015 ]
Hello Gib, I think it depends what inputs and outputs you use. Otherwise there is a conversion stage. I am going in AES/EBU and XLR out. This is the only DAC I have heard that sounds like a high quality reel to reel. Long break in is true on this unit. [ BRETT W May 29, 2014 ]
And as Taylor C said, the unit is very quiet. With the volume set high and no sound playing, there is zero hiss or hum. It's hard to get that with a mixer. All of my muisic is stored on a desktop PC. I am not a DJ. This is a home installation. Any DAC will be a plus for you if your going to be using a PC to amp or receiver. Be sure to get a high quality stereo USB cable as short as possible. It does make a difference in sound quality. [ William May 27, 2014 ]
I not sure I understand your question. The M51 does have balanced XLR stereo outputs if that is what your referring to. I'm using mine with two 6000 watt Crown pro amps. The sound I get now is phenomenal compared to my previous setup where I was using a DI box. Good Luck! [ William May 27, 2014 ]
Yes. Unit is very quiet. [ TAYLOR May 26, 2014 ]