MBL N31 CD/DAC

The MBL N31 CD/DAC was the second of two pieces from MBL’s midrange Noble Line that was sent from Germany to the island for review. You can read about my musical adventures with the striking and powerful MBL Noble Line N51 Integrated Amplifier here. Much like that glorious looking component, the N31 CD/DAC is cut from the same cloth—a machined beauty of metal and gloss black reflectivity. 

Like all MBL components and speakers (MBL calls its loudspeakers ‘Radialstrahlers’—MBL Radialstrahler 120 review forthcoming), the N31 was designed from the smallest circuit up by MBL’s chief designer for over 35 years, Jürgen Reis. Reis is a legend, borne from the litany of outstanding equipment he has produced. It seems once you go MBL, you rarely look back. From the ‘entry level ‘ Corona Line’ through MBL’s ‘Reference Line’, all the gear looks expensive and consistently sounds expensive.

I received the most gracious email from Reis after the N51’s review publication last month. Usually, I receive a kind thank you note, but this was a lengthy email written in very good English (Reis is German) talking about his design journey, the N51 review, honesty in reviews and his gratitude. It was very much appreciated. 

I’ve seen or heard most MBL components during shows and at dealers. All are available in black or white with either gold or chrome accents. My wife’s one word when we uncrated MBL’s shipment was ‘wow’. Our review units were requested in black with gold trim, but, you can’t go wrong with any colour combination. And much like the N51 in my system playing its role as an integrated amplifier, the N31 CD/DAC was by far the most beautiful looking digital kit ever to grace my audio racks. MSRP for the MBL Noble Line N31 CD/DAC is $15,400. 

Our thanks once again to Tara and Jeremy Bryan of MBL North America for their assistance in acquiring the MBL components for review. 

Top: N31 CD/DAC. Bottom: N51 Integrated Amplifier.

My Use

The Noble Line N51 and N31 share not only visual cues (same colour & materials, same backlit ID atop the box, same 5” TFT screen with six active buttons for menu changes, etc), but also electronically when connected by what MBL calls ‘SmartLink’ (MBL SmartLink version 2.0, employed to network MBL devices with the exchange of status information). I connected the supplied Audioquest Cinnamon Ethernet Cable to the N51 and N31’s SmartLink ethernet ports which allowed both to share one MBL remote control. The fabulous remote control mimics many of the N31’s functions and is easily the most impressive remote control I’ve used with high end equipment. 

The large circular ID on top of the machine is a backlit touchpad—tap or press it to dim front panel screen brightness or turn off completely (when both screen and touchpad are off, the 5” TFT screen has a proximity sensor and will turn on when approaching the unit). When the backlit ID is off, the power button indicates a beautiful blue hue. The touchpad ‘off’ setting was recommended to me by MBL. 

When the N31 was in rotation, I kept myself mostly in the digital domain. Audiophilia readers know me as a vinyl guy, but the N31 was so special out of the gate, it kept me in my digital sandbox. I used very fine cabling and power cords (Allnic Audio and Anticables) when the N31 was attached to one of three integrated amplifiers in rotation—my reference Jeff Rowland Continuum S2, the N31’s Noble family member N51 and the newest integrated in for review, the $18,995 300B DHT Vinnie Rossi L2i ‘Signature Edition’ Integrated Amplifier. You’ll have to wait for the Vinnie Rossi review (April 2020), but there is a video teaser here (Please subscribe to our new YouTube Channel. Thank you.).

The N31’s wonderful backlit remote control. The large chrome ring is the volume control. And for initial N31 setup, MBL provides white linen gloves.

Features

This is where the musician in me parts company especially with many verbose digital reviews and manuals—lots of manufacturers have jumped on the ‘more is better’ bandwagon when producing digital boxes, adding filters galore, digital volume controls, with features and add ons aplenty, many of which are not needed and clog up what can already be a very complicated design. Remembering, uncomplicated need not be unsophisticated. And with Roon in the picture (the N31 has a late to the game native Roon Endpoint module which works fabulously), plus the addition of MQA and HiRes files, the landscape gets even more complicated. Not forgetting all the links on the websites for lengthy, involved ‘white papers’.

My practise is to try the filters as quickly as possible in order to report to you, eschew any type of digital volume control, then select ONE filter/setting that works musically for me. This has worked well for many of my digital reviews including the recent T+A DAC DSD High End D/A Converter ($4450) and the Mytek HiFi Manhattan DAC II ($5995), the former, quite simple and elegant in its (German) design approach, the latter, chock-a-block with filters and available add ons, raising its price just shy of $9,000.

The N31’s features include:

• Intersample Overload Protection Technology

• 4-path DA converter with soft transition between delta-sigma and multi-bit processing

• 3 selectable digital filters

• iPhone/iPad as source—bit-true and jitter-free

• 3-stage jitter reduction

• Resolution and sample rates up to 24 bit/192 kHz, DSD64

What the N31 does not feature is MQA support (Reis could not confirm whether MQA was a possible future update) or an SACD drive. More on this choice later. But, what the feature rich N31 does include is a very sophisticated, deep dive design by Reis minimizing jitter and intersample overload. It also includes a CD text recognition display (and full colour album art as part of its Roon Endpoint feature set), a CD slot drive that has been optimized to account for air turbulence and mechanical vibration (the CD drive and its bog standard Red Book playback is one of the glories of this machine), a fully-balanced signal path from the DA converter to XLR output and optically-isolated USB inputs with its own power supply (more on the two USB inputs below). 

Specifications

• 5 digital inputs (Toslink, AES/EBU (XLR), S/P-DIF, USB audio class 1, USB audio class 2)

• 3 digital outputs (Toslink, AES/EBU (XLR), S/P-DIF)

• 2 analog outputs (1 x unbalanced (RCA), 1 x balanced (XLR))

• SD-card slot for easy firmware and display content update

• Dimensions : 45cm (w) 45cm (d) 15cm (h)

• Weight: 39.7 lbs (18kg) net, 48.5 lbs (22kg) shipping

Notice the USB input names in the photo above, USB1 and USB2 (next to the LAN input). *Important note for highest resolution playback—the inputs should read USB 1.0 and USB 2.0—two altogether different resolution animals. Stupidly (logically?) I connected my Audioquest Carbon USB Cable into the USB1 input. After some head scratching re the lower than expected resolution, some cross referencing with the manual, and a very pleasant phone call to MBL headquarters (the customer service fellow was very happy I called to point out the possible confusion), we were back up and running in the USB2 input (2.0) at 24 bits/192kHz resolution. Qobuz was happy. I was happy. 

Resolution and filter choice are shown in a small strip at the bottom of the display. Reis’ and my favourite filter was ‘Minimum Phase’. Twas musical, defined yet refulgent with superb detail, air and transparency, much of which is lost on many redundant filters on other DACs. On the Qobuz and Tidal HiFi files or CDs played, whatever ‘natural’ means to you, this was it. FYI, the other two perfectly fine filters are ‘Slow Roll Off’ and ‘Fast Roll Off’. You’ll have fun playing your favourite tracks through all three, but I think you may settle on the designer’s and my choice. 

For my past several DAC reviews (including the musically superb $6995 Mojo Audio Mystique v3 DAC), I have preferred file playback via USB (accessing thousands of FLAC tracks stored on my Antipodes Audio CORE Music Server ($4350), a brilliantly quiet device which also houses my Roon Core). My predilection for USB over other digital inputs was the cause of my initial confusion regarding resolution. Then, after using the N31’s USB 2.0 input for a while, MBL really encouraged me to begin streaming using Ethernet and its Roon Endpoint Module (introduced in late 2018) rather than only the stored FLAC files. I used my own Audioquest Cinnamon Ethernet Cable ($70) as streaming tether (MBL wanted me to use either Audioquest Vodka or Diamond Ethernet Cables at ten times (or more) the Cinnamon’s price—as that was not possible, Cinnamon it was.

The streaming sound quality compared to Ethernet connections and cards on other machines I’ve used was revelatory. 

The N31 CD/DAC was matching with apparent ease some of the very best digital sound I’ve experienced. In particular, Bel Canto’s full Black system and dCS’ Rossini Player (Red Book) and DAC; both top of the heap systems sell for north of 50K, a full 35 large above the MBL N31.

As aural memory can rest deep in the synapses and be fleeting, don’t hold me to all the subtleties the dCS and the as yet unheard Black Control DAC (upgraded in 2019) can achieve above the MBL’s performance. I’m sure there are some. But, I’ve heard the very best digital in show rooms, dealers and in my music room, and much of it leaves me impressed, yet cold and unmoved. Different was the spectacular Rossini at the 2019 Rocky Mountain Audio Fest, this time heard via its SACD Transport box. It was wonderfully detailed and musical (see below for Reis’ reasoning for his Red Book choice over SACD for the N31’s player). The Black in its debut guise 5 years ago (an eon in digital design) was also intensely musical.

And that’s what I’m listening for—musicality. Many upper echelon boxes I’ve heard can get the details (galore), layers, power and subtlety, but it is the music’s essence through timbre, phrasing and emotion that all but the best designs miss. Herr. Reis has captured the soul of music in his design.

And I heard and experienced it almost immediately.

Listening

I began with the CD player. A lovely, very effective transport which accepts and ejects CDs gracefully and quietly. As I mentioned, the transport plays standard Red Book CDs; no SACD layer.

I asked Reis for his reasoning for choosing Red Book over SACD. Here are his thoughtful and detailed responses:

Good question - 3 reasons

1. The mechanical damping of the CD drive is optimized like a turntable, so the spiders are tuned between the maximum rotation speed of the platter (8.33 Hz for a CD drive) and the lowest audio frequency, you want to play back (20 Hz) and so is tuned to 12.9 Hz, and so is soft enough to let the drive swim for audio frequencies, but is stiff enough to have sufficient hold for the rotation.

Ok. A SACD drive rotates about 6 times higher than a CD drive, so at 50 Hz, but the lowest audio frequency is still 20 Hz. So you see, there is no way to "isolate" a SACD drive in that way, to be stable enough for the rotation of the disc, but isolate enough for the lowest audio band. In other words: Only with a CD drive and a "tuned" isolation, you can get this stable bass.

2. The laser for the CD drive does have a wave length of 780nm and the laser for a SACD drive of 620 nm. The wavelength of laser for the SACD drive is optimized for the best tracking of a SACD disc and would be to "nervous" for the regulation circuit for the CD disc. Only the longer wavelength of the CD laser, gives you a "smoother" regulation of the servo.

Beside hearing this, this can also be measured by the Pierre Verany test disc CBS test disc, where they have modification of the groove, like deeper and less deeper grooves, groves with higher and with lower density, with different Bit to Land ratio, with simulated finger prints, with gaps and missing data. All can be handled better with the suitably laser.

3. Air turbulence. When you open the N31 you will notice, that for all 3 axes, we have tilted "wings" to prevent any air turbulence. The angle and the damping material was chosen to fit best the rational speed of the CD drive. You can not optimize the same material / angle to different drive type.

So, I hope you see, why we have fully optimized all CD parts, to get the best out of a CD drive.

If you have further questions, don't hesitate to contact me as I can answer any question, to any of the MBL products ;-)

Best Regards
Juergen

As usual, Reis responded with very detailed, technical answers. All I can say was from the first bow stroke on Mischa Maisky’s cello, I was hooked on this spectacular CD drive and its musical abilities.

The track in question was the Latvian cellist’s spectacular performance with Martha Argerich, piano, of Schubert’s glorious Arpeggione Sonata. Originally on a Philips CD, the ESOTERIC Japan remastering captures Maisky’s beautiful tone and all its subtleties and power with Argerich sounding equally superb in her not-so-well-known role as accompanist. This is the CD I was to use for break in (50 hours, FYI).

I was so surprised by what I heard at first play, I remained in the music room for much of the afternoon. Cold, out of the box, with nothing but test bench hours (minutes, probably) on the N31, this magical device was conjuring musical tales of delight. Soft, un digital-like round edges, but with detail and cutting musicality when required married to the most delicate transparency, a deep soundstage and exceptionally precise imaging. For this musician, timbral honesty. Actually, I was more shocked than surprised. I left the room to let the CD and electronics get on with it and wondered whether I was hearing an anomaly upon power on? I was intrigued. However, my vinyl bias was about to get a spanking. 

No, after break in, the spaciousness of the chosen CDs improved, but that glorious tone of the cello remained. The air around the instrument and the tactile brilliance of thumb pizzicato arpeggios to emphasize cadences (both perfect and imperfect) was something that turned my head every time I heard them on the many repeats of this CD.

What I love most about vinyl playback, at least on my setup, is the tangible presence of players and singers, the almost magical replication of instruments and voices, eluded in the digital realm with the exception of the very best digital devices. I’ll remember Maisky’s sound on this spectacular CD for a long time. Not fleeting.

MBL gave me two CDs to demo the unit—both engineered by Reis: Concerto Köln—Live in Kempen playing Vivaldi and Sammartini, among others, and Martin Vatter’s incredibly engineered piano CD Homeland. Both highlighted the exceptional tonal character of the N31, its balance of tessituras and thundering, deep bass. Contact Concerto Köln and Vatter to buy these two exceptional demonstration discs, both featuring outstanding musicians and musicality (no Audiophilia affiliation).

Switching to FLAC files, the up to 24/192 playback was superb. Reiner/Chicago/Bartok/RCA Music for Strings, Percussion and Celeste (the 4th movement, ‘Molto Allegro’) was overwhelming in its power and the way the component unravelled the complexities of this purposely thorny score. String tone was particularly energized. What an orchestra! I think the days of ‘digitized’ strings (violins, especially) are over. Recently, I’ve heard inexpensive boxes get the weight and rosin right. As such, all strings on CD, FLAC files or streamed were very beautiful. Guitars and piano, too.

Streaming was a delight. The album art was Naim quality, the best I’ve seen on streaming devices. And the N31’s Roon Endpoint made life so easy. It streams up to 24 bit/192 kHz, DSD64. My 24/192 Kind of Blue sounded evocative with not too much ringing around Bill Evans’ piano and sax placement very precise, all with the N31’s ability to communicate the music and emotion. Interestingly, the CD standard 16/44.1 Qobuz Philips file of the same Maisky CD described above sounded wonderful but missed some of the roundness of the sound, the air around the cello and the laser-like instrumental imaging. Bits are bits, right?

So, even though the streaming of 192 files was spectacular and the Trondheim DSD Mozart Violin Concertos equally wonderful, I kept returning to my ever shrinking CD collection and the absolutely fabulous CD drive. It now consists of a selection of the ESOTERIC SACD remasters and a few sundry Red Book discs. Each of them, especially the ESOTERIC’s Red Book layer were stunning. In any case, CD, file or streaming, your digital life is covered both now and in the future.

Summary

I can vouchsafe for the N31 CD/DAC as the most beautiful digital playback I’ve heard in my system. It worked seamlessly as a digital component, appreciated high end cables, and was amplified by three very different devices, playing music beautifully through all. With Reis’ imagining of the digital world, you are in very musical hands. And much like its N51 Integrated Amplifier stablemate, the N31 is brilliant in all regards. Very highly recommended.

Further information: MBL