Devialet Expert, a new breed of amplifiers

There has not been another single product capable of making such a fuss in the world of high fidelity like the Devialet line of amplifiers … for ages it seems. And there has not been a single reviewer that I know of who did not want to pass some time with these controversial amplifiers, if only just to see what the fuss is all about. Including me.

Not that I have not heard them on numerous occasions. Devialet has a massive presence at audio shows and in dealer showrooms, not to mention that the brand has managed excellent sales around the globe. For a relatively young company, only founded in 2007, this is not small thing; one more a reason to peg my curiosity rev counter into the red zone.

Technical fuss

So what is Devialet Expert? Simple (maybe): A new breed of amplifier implemented around class A and class D operation or accordingly with the company’s marketing brochure the ultimate audiophile system.

Now here is the catch, there are several amplifiers that operate in class A+D, with the inefficient but highly musical class A acting as preamplifier/driving stage and the highly efficient “digital” part doing the heavy lifting in the output stage.

The difference between the “standard” class D amplifiers and Devialet is that, in the French designs, both stages work in parallel and in a certain way the class A is autonomous; the company’s engineers on several PR occasions removed the class D modules and the amp kept singing with just the class A part. Of course the class D is necessary and provides tremendous power; depending on the model, the output ranges from 120 to 400Watts @ 6Ω, but by pairing two units, that total can be beefed up to 800Watts. The technology goes by the name of ADH (Class A / Class D Hybrid) and marks it as ‘different’ from just about every other class D amplifier out there.

A bit more technical fuss

Under the slim box hides a double digital conversion section, a DAC now capable of DSD and 24bit/192KHz PCM, and an analog to digital converter (ADC) which will digitize all incoming analog signals. This is probably the biggest shortcoming of the Devialet devices, meaning that while you can connect everything you want, by channeling the signal through an ADC, part of the potential benefit from, say, an external high-end DAC or phono stage, gets lost. Is this a problem? Depends on how good the internal DAC and digital phono stage are. We will get back to this later on.

Connectivity is guaranteed through a series of RCA inputs (no XLRs) that can be individually assigned to perform any given function. You fancy two independent phono stages, each one adjustable for capacitance, gain and resistive loading, or maybe several digital coaxial inputs for your CD and SACD transports? All you have to do is configure the device to your needs. A Devialet is meant to be used mostly with their own digital circuitry, so besides the RCA inputs, a complete series of digital connections is there waiting for you (USB, optical, AES/EBU), along with an Ethernet port. WiFi is also an option, but I faced several drop outs with hi-res music, so I preferred simply using wired Ethernet.

Set up

Besides the aforementioned Wi-Fi and Ethernet options, I also used the home-brewed Raspberry Pi linux based headless streamer for my time with Devialet. On the other side of the Ethernet cable comfortably sits a Synology NAS with 4 TB of high-resolution music. The digital front-end also included my personal reference DAC, the Rockna Wavedream, a sign magnitude design built around the famous MSB platinum modules with a proprietary FPGA receiver, custom filters and femto clocks taking care of the jitter.

On the analog domain, and in order to experience how good the internal digital phono stage was, I used the ZYX 1000 Airy3 low output MC cartridge and the ASR basis exclusive phono stage. Turntable was the classic Garrard 401, with custom plinth and external motor controller for lower wow and flutter with a Van den Hul wired Kuzma Stogi tonearm. Rest of the cables came from Nordost Norse 2 line.

My resident amplifier reference is the three chassis ASR Emitter I Exclusive. The speakers used throughout the entire review period were my ATC 100SLs; but as these are not among the SAM-ready models, a visit to a local importer helped immensely in assessing Devialet’s digital-signal-processing feature, by way of a pair of Audio Physic Virgo 25 speakers. On that occasion, the 400 was paired with the Primare NP30 streamer, while cables remained Nordost.

Yes, seems like a rather complicated setup, but the Devialet are what I would describe as “modern” electronics, which will take care of all possible necessities by offering a DAC, WiFi module, phono stage and gobs of power, under the sexiest package ever designed. This of course is a reviewer’s nightmare because each function needs to be assessed on its own, and then the overall picture must be drawn.

Setting up is a different story

The Devialets do not simply look the part of amplifiers designed in the 22^nd century and time-traveled back in 2015, they also behave like that. There is not much to do with the single on/off button sitting on the front plate, but there is quite a lot to be done with the SD card inserted in the back, right above the Ethernet connector. Each Devialet customer can access a configuration panel through the company’s website and start clicking on the various parts of the amplifier in order to customize every single function. One phono stage is not enough? How about two or even three? Each can be configured to properly match a different cartridge. Capacitance for MM carts, impedance for MCs, equalization curves and obviously gain can be fine-tuned via the web interface on the company’s site. Each input can be set to convert into 24bit/96kHz or 24bit/192kHz, but Devialet suggests you use the former as it offers the lowest amount of noise. Through the same web portal, you can attach a second Expert, in my case another 200 in order to make a pair of monos that were then capable of 400Watts (into 6Ω) per channel. Besides doubling the raw power, this provides double the inputs too. Working your way through the Configurator is simple and rather intuitive; bridging the two units requires a single coaxial cable along with the obvious reprogramming of the SD cards. After each tampering with the configuration setup, a file is downloaded and written to the SDs, a system reboot follows, and then we are good to go.

During the review period, I noticed that the Devialets were running hot; temperatures rose above 45°C and close to 50, as indicated by the internal thermometer, but I was assured that even when they go past beyond 50 this is normal, after all, that class A operation dissipates some healthy heat! With the sole exception of the WiFi streaming function, both units performed flawlessly during their stay.

J’adore French styling!

If you ask a sixteen year old to design an amplifier, he will probably throw down a black box. If you ask the same question to a seasoned audiophile he will probably throw down another black box only this time he will design massive heat sinks to both sides. Devialet is nowhere close to resembling either of those boxes, in fact it is nowhere close to looking like an amplifier at all. It is very slim, with just one tiny button in the front and a small LCD display on top. All cables and connectors are hidden out of sight by a sliding cover made from the same hand polished, titanium-colored metal that covers the entire chassis (and makes photography a real nightmare). Chances are, you have seen a Devialet Expert live already, so you know how much better looking are in flesh than what my photos portray them.

The remote control should have an entire review dedicated in Art Jewlery magazine; it is beyond sexy. Sublime. Made from the same polished titanium material, it features a central knob that provides the best sensation I have ever felt from a controller, bar none. Below the central knob, three little buttons take care of functions, such as source selection, mute and tone, though they can be reconfigured to act like everything else one might want from an RC. Your non-audiophile “better half” will fall in love with it, and when you tell her that Bernard Arnault, president of Louis Vuitton is among the major investors of Devialet, she may love it even more. If there is such a thing as a WAF (wife acceptance factor), this will pass with flying colors.

Sound of the 21^st century

Looks as modern as these with functionality in a pure 2.0 era; the sound should be no less than stellar.

Measurements, actually, are beyond reproach. The company vaunts vanishingly low THD+ noise, output impedance of 0.001Ω and 133dB S/N in dual mono mode. The Devialet Expert realizes a staggering 88 patents, which implies some very serious engineering behind the façade.

A recording with transparency and delicacy like few others is Antonio Forcione’s and Sabina Sciubba’s Meet me in London, courtesy of the Naim label. This was actually the first ever 24/192 album coming from Naim, a laborious remastering by well-known sound engineer Tony Platt of The Rolling Stones and AC/DC fame, who managed to preserve the duo’s exquisite take on jazz standards. Forcione, being a true maestro of acoustic guitar, plays like there are no frets underneath the cords and his fingers simply slide in the most melodic fashion. Being perfectly accompanied by Sabina’s brilliant voice, and not much else, the end result is alarmingly simple music, but just because it is so simple, it is also easily misinterpreted by electronics. In fact there is nothing that could hide an unnatural tone in those guitar strings or that sensual voice. The Devialet have transparency to sell, the strings come out in vibrant colors but without the piercing character of other digital era amplifiers. Coming to think of it, the Devialets should not be put next to other class D designs as they share little in their architecture or sound with the run of the mill Hypex and ICE-powered amps. Colorations were almost nonexistent, the hard to get female voices were a pleasant surprise and it soon became clear that these would provide some hard competition to my beloved ASR electronics.

The perception of clarity, along with speed and ultimate precision, was palpable on Beethoven’s The Tempest sonata as played by rising star pianist Artur Pizarro (FLAC 24/96 Linn records). Interestingly, Pizarro made a very personal decision when it came down to his instrument of choice, not the standard Steinway or Bosendorfer piano, but a more nimble Bluthner, known for a sharper, “faster” (if I am permitted the term) presentation. During the Allegretto, the dual mono Devialets proved that they can control the big 12” woofers of my ATC SCM 100SL speakers with authority, and yes, these speakers literally strive for power and control. Extension was excellent; the system portrayed the full 8 octaves of the piano without sign of roll-off. A true tempest it was! Codas, however, were shorter than expected — or maybe they should have not been expected to last as long as with class A-AB amps?

Reviewers often use Mahler’s Resurrection symphony as an example of highly complex and demanding composition, one which will separate the wheat from the chaff, and they do so for good reason. If a single link of the audio chain cannot handle the 100 (or so) instruments of the Budapest Festival Orchestra and chorus playing and singing all unison under Ivan Fischer’s direction (Channel Classics 24/192 Studio Master HD), like a natural intermodulation distortion test — only with many, many more main frequencies injected at the same time and their harmonics filling the space making things even harder for audio systems — then the end result will be closer to mashed potatoes than music. Here is where the Devialet 400’s strength is more obvious; those terrific measurements clearly come handy. Low distortion, excellent driving capabilities for the pair of the 400 mono configuration (not so much for the single chassis 200 when paired with the demanding ATC 100SLs), result in the possibility of discerning rows of bows one above the other; a classic music enthusiasts dream … if not exactly a necessity for realistic performances.

Sam?

Not the piano player in classic film Casablanca, but Devialet’s Speaker Active Matching, aka SAM, was launched (like in all things Devialet) with great glamour a year and a half back in Munich, during the annual audiophile pilgrimage. I still recall that room, a pair of B&W 800 speakers sitting something like 20′ apart and tons of people trying to grasp the differences this DSP has to offer. I steered away after a couple of minutes; that was closer to a dual-mono than stereo playback. Sam the pianist came to the rescue of awkward moments between the Bogart- Bergman- Henreid triangle, while the Devialet engineers used this DSP function to obtain every last drop of bass performance from the speakers. In order to achieve this goal, the company’s engineers study each speaker and measure parameters such as driver excursion, movement speed and so on, then use this data to adjust how the amplifier handles the speakers, and especially their lower frequencies. The promise is that your speakers will be driven to their limits — but not beyond.

At the time of this review, my ATC 100SL were not included in the ever-growing SAM ready list, so I had to pay a visit to a local dealer and listen to the exact same 400s paired with the Virgo 25 speakers from German manufacturer Audio Physic, speakers that I am familiar with. The showroom responsibles were kind enough to reserve a demo room just for me, so I spent half a day switching the SAM on and off, again and again while playing all sorts of music without being able to make any conclusive decisions.

It clearly does something, but then again not that much, even in tracks like “Drum n Bassa” from Infected Mushroom, where in theory the woofer excursion is more than extreme, it is sick. Do not try this at home kids! Pushing hard on the volume, it appears that the bass is slightly held back while the rest of the frequencies are still there, at least as far as SPLs are concerned. Not a huge difference, it’s noticeable, but only if a tight A-B was performed and volume was L-O-U-D. On more melodic tracks (just about every other composition made in mankind’s history is more melodic than Infected Mushroom), the SAM DSP seemed to alter the mids too, or to be more precise, some harmonics generated from the lower frequencies went missing. So SAM is a function you will have to test for yourselves and see if it pulls some magic for you. Not something that I felt missing when back at my place, in company with my ATCs.

A relationship with benefits

Devialet offers a highly configurable phono stage, among the most versatile in the market. A record that perfectly matches Devialet is Poulenc’s Concerto for Two Pianos, the quintessence of his compositions, with Eden and Tamir on glorious Decca sound (SXL 6551). Composer, LP cover by Matisse, and naturally the amplifiers are all French — there must be some synergy in there. Playback was extremely dynamic, detailed and precise, but with no old fashioned analog charm, some of which is apparently sacrificed in the ADC conversion. Here is the main handicap of this work of art, all analog inputs are converted to digital before the amplification begins.

If you already own a fancy phono stage, or a high-end DAC, then be prepared to leave some of their magic before entering. I gave it a try with both my ASR Basis Exclusive phono stage and my reference DAC, the Rockna Wavedream. Both of these machines cost close to what a brand new Devialet 200 would set you back, so they are not a logical pairing. For whatever it’s worth, both gave a slightly improved sonic result when compared to Devialet’s Burr Brown DAC and digital phono stage, but not to the extent one would expect. This is only natural as the signal must go through an additional transformation from the analog to the digital domain. Same tracks sounded only a bit better with my external devices in terms of depth of stage and tonal “richness”, but that bit was probably not enough to justify the cost of pairing those devices to the Devialet. The sole fact that the internal phono stage and DAC are comparable to the ASR basis exclusive and Rockna DAC means that you probably should not care much about upgrading any time soon, if ever.

Guilty Thoughts

Is this mandatory ADC-DAC thing a true handicap, a deal-breaker perhaps? The answer is no. And yes. A bit of both, as it depends on who you are.

Despite being relatively young, I do regard myself as an old-fashioned audiophile. I like big speakers, huge amplifiers, running hot while operating in class A (or heavily biased in AB) and offering the illusion of warmth in the sound. I like ladder DACs that sound much more “analog” in their timbre. Not only do I like the sound, I admit enjoying the looks of stacks of equipment too. The more the better, the bigger the more they have my name on them.

My rig has 250 lbs of amplification, including the 3 external power supplies for the ASR Emitter amplifier and ASR Basis phono stage, not to mention my Rockna DAC, and a small Linux based music streamer. I could swap all this with just a single device, a single Devialet Expert 200, which on paper offers the same power plus a phono stage, WiFI streamer, 24/192 PCM and DSD-capable DAC, not to mention the coolest remote I have ever laid my eyes (or fingers) on. Just don’t hold your breath because it won’t be happening any time soon.

You might be different than me, maybe a new breed of audiophile who loves efficiency, modern aesthetics and all in one functionality. Maybe you enjoy the idea that your entire system is hanging on a wall and a pair of speakers is the only thing that calls you out as a music lover. One of the reasons why this product has such a following is that it clearly departs from everything else and in all possible ways. The form is slick, mirror polished and has no knobs. Typical high-end power cords will not even fit with the cable cover on because there is not enough space for the big IEC plugs that usually come with them. Speaker cables? I had the same problem with my Signal Projects spade terminations which won’t make it inside the binding posts. Does it matter? I think not.

All this is so “old school” audiophile. Actually, during my period with the Devialet, I came to think that those who choose such a revolutionary device care little about cables, external DACs and phono stages, and I would almost bet that aesthetics, all in one functionality, software controlled upgradability and compact design count a lot (or count a lot more) in their decision-making process. Sound is also important for those potential buyers, after all if they were not music lovers they would not spend the 7.000 euros for the 200, let alone the 12K for the 400.

Is sound the sole objective here? Definitely not. Devialet is different, revolutionary in what it does and controversial in what it does not. The class A part of it sounds good but what arrives at your speakers is a big chunk of the class D part running in parallel and the overall sensation is not typical in so called “high end” terms. No midrange magic, no codas in the piano strokes and no coloration added to the music. The ASR is what I would call “the warm side of neutral” with some 30Watts in class A and the rest in AB. Rich and detailed, closer to my preferences and probably those of many “old fashioned” audiophiles. Driving is on par with the Devialet 400s, if not better despite the mere 150Watts/8 Ohms, which may have to do with the massive power supplies (1 Farad of filtering capacitance and big transformers with blazing fast Schottky rectifiers), and in the end their grip on the big 12’ woofers is just phenomenal.

La Fin

There are two ways I could end up this long review. Two images actually.

Think of Devialet as a stone thrown on still waters. The ripple created in the high-end scene at the site of the first contact was and still is significant. A second, smaller ripple follows and a third even smaller after that. How big and long-term the impact will be has yet to be seen, but Devialet has definitely created a ripple very few others managed in recent years. And they kept throwing stones; the Phantom, for a notable for-instance, is another innovative product coming from the same French team.

The second image comes from the Munich High End show — a gorgeous horse breaking through a wall of light. That aesthetic masterpiece stands up as Devialet’s breakthrough technology, blended with a touch of fashion and sets new standards in this old market.

Are you intrigued by all this? Do you feel modern enough to own this new breed of electronics?

Specifications

Devialet’s complete Specifications

MSRP Devialet 200: $9,495, additional slave unit (for the 400 combo): $7,995

Associated equipment

• ATC SCM 100SL speakers
• Audio Physic Virgo 25 speakers
• ASR Emitter I HD amplifier with external Akku
• ASR Basis exclusive phono stage
• Garrard 401 turntable, NMC motor controller, Kuzma Stogi tonearm, ZYX 1000 Airy 3 LO MC cartridge
• Rockna Wavedream Platinum DAC
• Signal Projects Hydra speaker cables
• Nordost Norse 2 Heimdal cables
• Stereolab Superleggera Blue IC
• Belkin Gold USB cables
• Raspberry Pi 2 streamer (linear PSU, Archphile OS)
• Primare NP 30 streamer
• Windows 7 64 with Foobar v1.3.2