NAD Masters M50.2 Digital Music Player & Aurender A10 Music Server

Notes on a Year Spent Streaming

Equipment report
Digital-to-analog converters,
Music servers and computer audio
NAD Masters M50.2 Digital Music Player & Aurender A10 Music Server

NAD Masters Series M50.2 Digital Music Player
Understand that I’m not so naïve as to be unaware that all music servers are computers, but at least they have the good grace not to look like computers and the good manners to occupy a place on the cabinet with the rest of the electronics. According to Stidsen, this was the principal rationale behind the M50.2: “Conceptually, computer audio without the computer, a completely self-contained music source that isn’t compromised by all the issues that can interfere with music when using computer hardware. Computers are general purpose devices that were never conceived with music as their primary function. The M50.2 can happily live in the listening room, isolated from email, photos, social media, software updates that undo your music settings, viruses, etc.” 

The 50.2 combines, albeit with considerable upgrades and features, NAD’s earlier M50 music player and M52 Digital Storage Vault into a single chassis. In effect, it’s three components in one: music server, storage drives, and CD player/ripper. When the 50.2 first appeared in 2017 I believe it was unique in offering this specific combination of components, and since then to my knowledge only the Aurender ACS10 offers a comparable combination (see Steven Stone’s review in TAS 300). The storage is 4TB divided over two drives arranged in a mirrored RAID configuration, one hot or active, the other cold and used strictly for storage and backup. That way if the hot drive fails, you still have all your files intact on the back up. 

Getting the 50.2 up and running is a simple matter of connecting it—Wi-Fi, Bluetooth, and Ethernet are available (I choose the last because I believe a wired connection is always superior)—plugging it in, downloading NAD’s BluOS app, and you’re off to the races. The only essential component missing is an integral DAC, but NAD figured that so many potential buyers already have a DAC they like, whether stand alone or built into their control units (such as the company’s own Masters Series preamp and integrated amp, to which the 50.2 is a logical companion). Then, too, separating music server and DAC allows for upgrades to either without having to dispense with the whole component. Beautifully styled à la NAD’s other Masters Series components, the 50.2 is designed to compete at the highest possible performance level, its substantial chassis finished in brushed aluminum and black accents with first-class parts and build, the packaging and presentation outdoing those of many luxury-priced components (the manual comes in a leather-jacketed USB stick). Given everything it has on offer, the $4399 retail seems to me quite reasonable, hardly surprising considering it’s an NAD.

Although an immensely sophisticated piece of equipment, the 50.2 is, according to NAD, essentially a “software defined product, meaning that much of the functionality of the system is defined by software not hardware”; thus upgrades are integrated by simply updating the 50.2’s software. The brains of the unit consist in the aforementioned BluOS, the company’s proprietary music-only operating system accessible through the BluOS app, which I downloaded to both my iPhone and my iPad. A quick look at the 50.2’s front panel reveals no knobs, buttons, or switches, only a touch-screen display, most of the functionality residing in the app, including even that of the CD ripper (no remote handset is included or necessary). To be sure, you can operate it from the touchscreen, but the app is much easier. Insert a CD, the screen asks whether you want to rip or play it. If you select play, there will be a short interval between hitting play and hearing music because the CD is being buffered, a good thing inasmuch as, theoretically at least, this translates into more accurate reproduction since the playback will be from the buffer instead of the spinning disc (those more technically savvy than I say this preserves the integrity of the spaces between the bits).

I have no plans at present to transfer my CD library to storage drives, but if I did, the ripper function alone would tempt me to purchase the 50.2 for three reasons. First, according to Stidsen, “PCM from the disc is read into memory as a first action. Then for playback, once a small buffer is established, it is re-clocked by the M50.2’s precision clocks (one for 44.1k and multiples, and one for 48k and multiples) and sent onward to the DAC, not relying on the CD drive for clock integrity. For ripping we do a ‘bit perfect’ rip where we note the checksum (total number of bits in the file) from the metadata and continue to rip until we get all the bits. After the entire disc is captured in RAM, we then apply any chosen lossless (FLAC) or lossy (320kbps MP3) compression and save it to the onboard hard drives. It can also be saved as a WAV file with no compression. In both playback and ripping we don’t rely on CIRC correction algorithms to ‘fill in’ missing data like a CD player does. So, in theory the M50.2 can sound better than the same CD played on an ordinary CD player that relies on the mechanical drive for jitter performance and uses interpolation filters to prevent gaps in playback of less than perfect CDs.”

Second, the process couldn’t be easier. Once you select the format (via BluOS), it becomes the default; should you change it, the new selection becomes the default. Otherwise, operation is completely automatic: Insert the CD, select rip, and a while later the files are on the internal hard drive, complete with metadata and cover art (displayed on the LED screen and whatever device the BluOS is on). Third, BluOS easily organizes and accesses your ripped CDs. My experience indicates they are sonically at least identical to your CDs or better owing to the buffering and any improvements your choice of DAC may bring (assuming it’s better than the one in your CD player). I’ve done my own ripping using computer and third-party applications and I hated it. When it comes to transferring, organizing, and making accessible ripped CDs, I have no experience with anything out there that comes close to making the task as easy and foolproof as the 50.2 (Aurender’s ACS10 and A30 doubtless rival it in this regard, but I’ve no experience with them).

And streaming music? It’s as easy as the ripping. Like most music-streaming applications, BluOS is able to integrate all the popular streaming services. Many of the features of these applications are of little or no interest to me, like playlists, which I never make. I rarely listen to “songs,” that is, individual selections (unless for purposes of research and comparison, or reviewing components)—I listen to pieces of music, that is, compositions, typically whole albums. When my wife and I want background music for, say, a party, I just load several appropriate albums into the queue and let them run their course. I do like the radio features because I have no tuner in my system, so this lets me access Los Angeles stations such as KUSC, KPCC, and KCRW through my main or office systems, not to mention a great number of stations around the country. But most of my time with the 50.2 was spent streaming music via Tidal or Qobuz. How does it sound?

The answer, so far as I am able to determine, is that it sounds like the source and whatever DAC it’s going into. In the year I’ve been using the 50.2 I’ve partnered it with four different DACs: a Benchmark DAC1, a Benchmark DAC3, the DAC built into my McIntosh C52 preamplifier, and the DAC built into the Marantz Ruby SA-KI player I recently reviewed. Go back and read my reviews of the C52 (TAS 283) and Marantz Ruby (TAS 299) and that’s how it sounds. As for the Benchmarks—a review of the new DAC3 is forthcoming—there was that same impression I take away from all Benchmark products: coloration-free neutrality that bespeaks absolute transparency to the source. Nor was I ever able to detect any distinctive overlay that persisted from one DAC to another. In other words, if the 50.2 is imparting some characteristic of its own to the reproduction, its contribution is so minute as to be undetectable or obliterated by other factors such as the sound of the source or whatever residual sonic characteristics may inhere in the DACs (precious little in the McIntosh or Marantz, effectively none in the Benchmarks). Not that the 50.2 is capable of being all things to all users. Its sample rate is 32kHz to 192kHz, 16/24 bit, but there is no support for PCM 32/384 or for any DSD. When the 50.2 was introduced NAD announced that within a year a software update would provide DSD capability. That was optimistic, and two years later the company has given up trying. In our last conversation Stidsen indicated that consumers committed to DSD will have to go to other products to get it.