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- Written by S. Andrea Sundaram S. Andrea Sundaram
- Category: Full-Length Equipment Reviews Full-Length Equipment Reviews
- Created: 01 March 2015 01 March 2015
If you’ve been paying any attention to high-end audio over the past several years, you’ve probably heard of Devialet. The French company launched its first product, the D-Premier integrated amplifier-DAC, at the 2010 High End show, in Munich, and has been receiving rave reviews from the audio press ever since -- including Doug Schneider’s review of the D-Premier for SoundStage! Hi-Fi, Hans Wetzel’s review of the 120 for SoundStage! Access, and Jeff Fritz’s review of the 400 dual monoblocks for SoundStage! Ultra. In fact, I couldn’t find a review from any credible source that was anything less than enthusiastic.
The subject of this review isn’t another amplification product from Devialet, but a complete two-channel system, the Ensemble ($9995 USD), comprising Devialet’s 120 integrated amplifier-DAC and a special edition of Atohm’s GT1 two-way loudspeakers. By design, the system is more than the sum of its parts, as I’ll explain anon.
Devialet’s first core technology, Analog Digital Hybrid (ADH) amplification, was developed by company cofounder Pierre-Emmanuel Calmel, an engineer formerly at Nortel France’s R&D labs. In the Devialet amplifiers, the output of a Texas Instruments PCM1792 digital-to-analog converter is connected, through a single high-linearity resistor, to a high-voltage, low-power, class-A amplification stage that directly drives the speakers. Current is supplied by a multistage class-D amplifier operating in parallel. Devialet’s white paper likens the technology to power steering in an automobile: manual control of the steering wheel directs the hydraulic system, which provides the power necessary to turn the tires. This topology is claimed to deliver all of the linearity and refinement of a class-A amplifier with the power and efficiency of a class-D circuit.
The second proprietary Devialet technology is Speaker Active Matching (SAM). All loudspeakers listed on Devialet’s website as SAM-compatible have been measured by Devialet, and their electrical, mechanical, and acoustical properties modeled. SAM uses digital signal processing to apply a time-domain correction to the audio signal, to account for phase shifts and nonlinearities in the speaker. The result, according to Devialet, is an acoustical signal from the speaker that is more faithful to the source. More details on ADH and SAM can be found on Devialet’s website.
The Devialet 120 integrated amplifier-DAC measures 15”W x 1.5”H x 15”D, weighs 12.4 pounds, and can be placed horizontally on a shelf or vertically on a wall. Bought separately, it costs $6495. The chassis is milled from a solid block of aluminum, to which a chrome finish is applied. Looking at the 120 on a shelf, the front panel has only a teardrop-shaped button for power; an OLED display on the top panel gives information about volume setting and source. The display can also tell you the incoming sample rate and system-diagnostics information.
Control of the 120 is by means of a heavy, square, RF remote with a large volume knob and buttons for Power, Source, Mute, and Tone, all reconfigurable for other purposes. An easily removable rear panel grants access to the connections: an IEC power inlet, speaker binding posts, in and out triggers, an Ethernet port, asynchronous USB, standard and mini TosLink, and four RCA jacks. The RCA jacks are configurable in a number of different ways -- e.g., as two coaxial digital inputs and a moving-magnet phono input; or as one digital input, one digital output, and a stereo pair of analog line-level inputs. Also on the rear panel is the SD card slot that provides the means of configuring the 120 and updating its firmware.
The Devialet 120 is rated to deliver 120W into 6 ohms (hence its name), 90W into 8 ohms, or 180W into 4 ohms. The switching power supply is claimed to support 600W of continuous power or 3000W in short bursts. The total harmonic distortion and noise are specified as 0.001%, as is intermodulation distortion. The 120’s signal/noise ratio is an astonishing 130dB -- nearly as good as the PCM1792 chip on its own. Output impedance is claimed to be a very, very low 1 milliohm, which should mean precise control of nearly any loudspeaker and with no modification of its frequency response.
The other half of the Ensemble system is the pair of Atohm GT1 SE loudspeakers. Atohm may not be well known in North America, but the company’s drivers can be found in many high-end speakers, including those from Triangle and Elipson. The GT1 SE is a two-way, stand-mounted design measuring 12.9”H by 7.8”W by 10.3”D. The cabinet is made of MDF, and curves slightly toward the back. Finish options include black or white lacquer or real rosewood veneers. My review pair was in white, and I have zero complaints about the quality of the lacquer; these are some very attractive speakers.
The GT1 SE’s driver complement consists of a 1.1” fabric-dome tweeter with a neodymium ring-motor assembly, and a 6” midrange-woofer with a variable-compliance surround said to improve pistonic motion. Both drivers are from Atohm’s Absolute series, and are crossed over to each other at 2.5kHz using a first-order network that Atohm says has been optimized for time coherence. On the back of each speaker, below the port, is a badge with the Devialet name and a single pair of high-quality binding posts. Naturally, the GT1 SE is among the speakers that Devialet has modeled for SAM.
To set up the Ensemble system, I placed the Atohm speakers atop 30”-high Plateau stands filled with kitty litter, and connected them to the 120 with the supplied speaker cables, these terminated with spades at the speaker ends, and bananas to plug into the 120’s binding posts. I then had to configure the 120, using Devialet’s online Configurator to select input options, enter information about my wireless network, and turn on SAM with the Atohm GT1 SEs selected as my speakers. The resulting configuration file is then downloaded and copied to the included SD card, and the amplifier’s configuration is updated once the card has been inserted in the 120’s slot. To feed the Devialet music from a computer, Windows users will have to download and install Devialet’s USB driver (Mac users can skip this step). Alternatively, you can download their Asynchronous Intelligente Route (AIR) application (Windows/Mac) to stream music over Ethernet or Wi-Fi. All of these operations are straightforward for anyone with even basic computer experience, but your Devialet dealer should be willing to configure the system for you.
At this point, I was ready to hear some music. The AIR application should appear as an available output device in your media player of choice. The problem I had was that the application would lose its connection to the 120 as soon as I started playing music. I went through the relevant topics on Devialet’s support forum and adjusted buffer lengths, used a Wi-Fi network analyzer, and switched my Wi-Fi to the least crowded channel. While I eventually did get Wi-Fi streaming to work, it was plagued by static and dropouts at 96kHz, and it wasn’t reliable even at 44.1kHz. This, despite the fact that my wireless router was separated from the 120 by only about 25’ and one thin wall.
I ended up using an older laptop connected to the 120 via USB. Since that laptop was streaming the same data from my NAS, I can’t buy the argument that high-resolution music streaming is too data intensive for reliable use over Wi-Fi. Another option would be to use a wireless Ethernet bridge (less than $50) plugged into the same power source as the amplifier, and run a cable into the 120’s Ethernet jack. Perhaps Devialet will improve the reliability of their Wi-Fi streaming in the future, but for now, I don’t find it reliable enough to be a bona-fide feature. Not having ripped all of my CDs, I also connected a Harman/Kardon CD player/recorder to the 120 via a coaxial digital cable (my Ayre Acoustics C-5xeMP has only an AES/EBU output).
The Ensemble system immediately impressed with its portrayal of space. In a recording of Debussy’s Nocturnes conducted by Claudio Abbado, the players of the Berlin Philharmonic were spread out on a soundstage that extended well outside of the speakers to left and right (CD, Deutsche Grammophon 289 471 322-2). The front of the orchestra began somewhat behind the speaker plane and continued well behind my room’s front wall. The offstage trumpet part in the second movement, Fêtes, was muted by distance but still rich in detail, and the women’s chorus in the third movement, Sirènes, appeared as a curtain behind the orchestra. What’s more, that soundscape had a marvelous sense of continuity in both lateral and depth dimensions. Not only was the placement of each orchestral section obvious, so were the positions of the players within the sections -- and the Ensemble did a splendid job of keeping the instruments integrated into the ambience of the Jesus-Christus-Kirche, where the recording was made.
Faithfully reproducing the interactions between instruments and venue is crucial with recordings of French horn, as the majority of what we hear from this instrument is reflected sound. The recording engineers did an admirable job of capturing that mix of direct and reflected energy on Chamber Music for Natural Horn Ensemble (24-bit/44.1kHz FLAC, Resonus Classics), an album of works by Jacques-François Gallay (1795-1864) performed by Anneke Scott and Les Chevaliers de Saint Hubert. The Devialet system did an equally fine job of letting me hear the sound bouncing back from the walls of the recording space.
Though the Ensemble could render an expansive soundfield, it didn’t do so by exaggerating what was on the recording. For example, in soprano Juliane Banse and pianist András Schiff’s disc of songs by Debussy and Mozart (CD, ECM New Series 1772), Banse’s voice was placed unambiguously at the center of the soundstage, somewhat behind the speaker plane, the piano farther back. Both voice and piano were bathed in warm reverberations, but despite the dozens of times I’ve heard this recording through many excellent systems, listening through the Ensemble was the first time I’d really noticed that the reverberant field was different around each, with slightly more ambience around the piano -- but I couldn’t say how much was due to mixing in the feeds of the ambient microphones and how much might have been tonmeister Stephan Schellmann’s addition of artificial reverb.
The same time coherence and resolution of low-level detail that made for exemplary portrayals of ambience also gave great shape to individual notes. The softer notes in the piano’s top octaves in “Clair de lune,” from the Debussy songs disc, had a rounded attack with a long decay, while staccato passages elsewhere were far more percussive. That differentiation in touch also enhanced my enjoyment of Hélène Grimaud’s fabulous album of music for solo piano, Resonances (24/96 FLAC, Deutsche Grammophon). Musically relevant details, such as the bouncing of the string players’ bows in the collegno battuto passage in Dream of the Witches’ Sabbath, from Berlioz’s Symphonie fantastique on a recording with Marek Janowski conducting the Pittsburgh Symphony Orchestra (SACD/CD, PentaTone PTC 5186 338), were likewise well served. Even details that are arguably irrelevant to the musical experience -- e.g., Stefan Schulz’s breaths or the clicking of his bass trombone’s thumb triggers on his Berlin Recital (16/44.1 FLAC, BIS) -- were depicted with remarkable fidelity.
Some components seem to force detail at the listener, which can quickly grow tiresome. That wasn’t the case with the Ensemble. The system’s incredibly low noise floor and freedom from distortion simply revealed all of those details for me to take or leave as I wished -- much as such sonic minutiae are experienced in the real world. That’s not to say that there couldn’t be a trade-off for being able to hear all of that detail. As with pretty much any pop album, the songs on the Beatles’ Magical Mystery Tour (CD, 2009 remastering, Parlophone 3 82665 2) are woven together from a collection of tracks recorded at different times and in different places. The Ensemble made it easy to separate the threads that make up the well-constructed “Penny Lane,” but some listeners may not want to hear the extent to which “Strawberry Fields Forever” is a hodgepodge of tracks. Even otherwise naturalistic recordings can have flaws that the Ensemble will expose. One example occurs at 1:27 into “Clair de lune,” where there is a clicking sound much like what one hears when a CD skips. Perhaps it’s an artifact of editing done to remove a clipped portion of the signal -- it occurs at the loudest part of the track. Heard through the Ensemble, the clicking can be categorized and put to one side, but a less resolving system will skim over such problems entirely.
Though my comments thus far have been related to the small scale, the Ensemble system also shone when I turned up the volume. Daft Punk’s Random Access Memories (24/88.2 FLAC, Columbia Édition Studio Masters) -- especially the final track, “Contact” -- demands to be played loud. The Ensemble obliged by delivering output levels in excess of what I could stand to listen to for more than a few minutes at a time, and did so without ever turning hard. Louder was just louder, as it should be but rarely is. The capacity to deliver high SPLs cleanly was also a boon to large orchestral works. The tremendous dynamic swings in Respighi’s The Pines of Rome, as played by the Minnesota Orchestra under the baton of Eiji Oue (24/88.2 FLAC, Reference Recordings), were slightly compressed, but far less than I would’ve expected from these relatively small speakers.
Bass performance was another area in which the Atohm speakers belied their small size. The kick drum in “Lose Yourself to Dance,” from Random Access Memories, not only had excellent punch but real weight behind it. And in “Within,” the downward sweeps in the spacey bass synthesizers went far lower than I would have thought possible from such diminutive speakers. Orchestral music, too, benefited from having a solid foundation. Still, the Ensemble couldn’t quite flex my walls with the bass synthesizers in Massive Attack’s Heligoland (CD, Virgin 609466 2), or vibrate my floor with Jan Lehtola’s recording of Kalevi Aho’s Symphony for Organ: Alles Vergängliche (24/96 FLAC, BIS).
Devialet specifies the GT1 SE’s -3dB point to be 25Hz with SAM engaged. This figure contrasts with the 45Hz lower bound Atohm gives for the standard GT1 without SAM. That’s a considerable difference, and one that I wouldn’t have credited had I not heard it for myself. Investigating the Ensemble’s low-end behavior with stepped test tones, I found the GT1 SE’s bass to extend well into the lower 30Hz region with SAM, while dropping off considerably after 40Hz without -- though I did have to keep the volume down in order for SAM’s protection system not to throttle back the woofers’ excursions. Musically speaking, the increased bass extension meant that orchestral bass drums sounded much bigger and fuller, and the synthesizers in Random Access Memories created a more complete sonic tapestry with SAM switched on. I believe the nearly full frequency extension was also at least partly responsible for the Ensemble’s sense of space.
In search of even greater bass output, I tried connecting my REL R-328 subwoofer to the 120, but that required disabling SAM -- obviously, the REL wasn’t part of the acoustic model. While the sub was able to fill out the rest of the bottom octave, the system lost some of the focus and three-dimensionality I’d enjoyed with SAM active. On balance, I felt it worth giving up some power and extension in return for keeping the other benefits of SAM. As ever, those who wish for truly full-range sound and/or huge sound output are advised to look for bigger speakers. But in order to maximize performance, it’s important to make sure that they are SAM compatible.
Finally, the basic tonal balance of the GT1 SEs was very much in line with that of other speakers that I know to measure close to flat, with just a touch of extra energy in the upper midrange. The result was that the timbres of voices and instruments were largely as expected. An excellent example was the sound of Miles Davis’s Harmon-muted trumpet in Relaxin’ with the Miles Davis Quintet (CD, JVC VICJ-60125). The Ensemble gave a believable balance of the top-end sizzle with the middle tones, and the extra midbass that comes from Davis’s trumpet being close miked. In particular, the GT1 SEs’ tweeters deftly walked the line between detail and extension on the one side, and nonfatiguing smoothness on the other. Harpsichord notes in London Baroque’s The Trio Sonata in 18th-Century France (24/96 FLAC, BIS) were crisp, and the violins had a good amount of bite. When writing about overbright recordings, I usually single out an example from the pop genre, but many older classical albums can be equally problematic. Through the Ensemble, the recording of Bizet’s Carmen with Regina Resnik, et al., and L’Orchestre de la Suisse Romande under Thomas Schippers (CD, London 443 871-2), was certainly too bright, but Devialet’s system didn’t exacerbate that brightness, and the album was still listenable.
To assess which aspects of the Ensemble’s sound were related to the 120 amplifier-DAC and which to the speakers, I tried the 120 with my usual speakers, the Esoteric MG-10s ($2800/pair when last available); the Atohm GT1 SEs with my usual combination of Ayre Acoustics C-5xeMP SACD/CD/DVD-Audio player ($5950) and Graaf GM50 integrated amplifier ($7500 when last available); and the Ayre’s analog outputs feeding the analog inputs of the 120 digitized at both 96 and 192kHz.
First, although I’ve used the GM50 with many different speakers over the years, and found it relatively insensitive to variations in speaker impedance as tube amps go, results with Devialet’s edition of the GT1 were not very satisfying -- the combination lacked the focus and precision of the Ensemble system. The MG-10s and 120 were a much better pairing. With their somewhat larger cabinets and slightly larger woofers, the MG-10s could go a little lower than the GT1 SEs without SAM, but with SAM active there was no contest: the Atohms played obviously deeper. The only two-way monitors I’ve reviewed that go as deep as the GT1 SEs are Wilson Audio Specialties’ Duettes, which have enormous cabinets and 8” midrange-woofers.
The Esoterics did reveal some areas in which the Atohms could be bettered. Although I didn’t notice any overt colorations in the GT1 SE’s sound, I did hear a slight obscurity in the lower midrange that reduced the texture of male voices and similarly pitched instruments. I’ve never encountered a speaker system that was truly indistinguishable from the real thing, but the MG-10s were more present and open, and simply a step closer to the sound of real instruments playing in my room. On the other hand, the GT1 SEs’ re-creations of soundstages were more sharply focused. And while the MG-10 is not an aggressive speaker, the GT1 SE is a little more forgiving of hot recordings.
The Graaf isn’t an especially tubey-sounding amplifier, but it does exhibit some of the characteristics typical of good tube designs. The Devialet 120 is by no stretch of the imagination edgy or hard -- in fact, the only solid-state amplifiers I’ve ever heard that can approach the 120’s resolution without introducing artifacts that become fatiguing over time have cost five figures -- but the GM50 is a little smoother. The Graaf’s soundstage was often more voluminous than the Devialet’s, but was no match for the 120’s precision. While different recordings had me preferring one amplifier or the other, I believe that the signal at the 120’s speaker terminals was closer to what was really on the recording.
Audiophiles have traditionally assumed that the more and bigger the boxes, the better the sound. In that sense, the emphasis of Devialet’s Ensemble on the shortest possible signal path and the fewest number of components is very non-audiophile. The traditional audiophile also enjoys trying different combinations of components to achieve his ideal sound, but a turnkey system like the Ensemble doesn’t fit that ethos either. So forget traditional audiophiles -- they comprise a small and shrinking market anyway. Devialet’s Ensemble is for the music lover who wants superlative sound quality in a package that doesn’t dominate the living space.
Regarding the Devialet 120, I find myself echoing the words of other reviewers. The 120’s combination of high power, extremely low distortion, and totally inaudible noise floor opened a pristine window on each recording, regardless of volume level, and did so in a manner that never became fatiguing. The Devialet 120 isn’t just good for the price -- it will put many much-higher-priced setups to shame. Devialet’s Special Edition of Atohm’s GT1 loudspeaker is a great complement to the 120’s strengths. Thanks in large part to Devialet’s SAM, the Ensemble is capable of bass output and dynamics well in excess of what you might expect from the small GT1 SEs. SAM also seems to enhance the speaker’s time resolution, resulting in excellent imaging. While other speakers can offer more bass, higher maximum output, and a touch more transparency, it will take some effort to find a pair that doesn’t give up something else to the GT1 SEs, and they will inevitably be bigger and more expensive.
The beauty of Devialet’s Ensemble system is that you can have truly excellent sound in a small, décor-friendly package for under $10,000 and with no effort. That’s a unique value proposition that I believe will bring Devialet great success.
. . . S. Andrea Sundaram
- Digital sources -- Harman/Kardon CDR 25, Ayre Acoustics C-5xeMP
- Amplifier -- Graaf GM50
- Speakers -- Esoteric MG-10
- Subwoofer -- REL Serie R-328
- Interconnects -- DH Labs Revelation, QED Silver Spiral
- Power conditioner -- Equi=Tech Son of Q
Devialet Ensemble System
Price: $9995 USD.
Warranty: Five years parts and labor.
SAS 10, Place Vendôme
Phone: (33) 502-155-682