The Devialet Expert 220 Pro is an integrated amplifier, but also a whole lot more to boot. Janine Elliot takes this £6990 French Fancy for a whirl.

Devialet is one of those companies that you just go “wow” whenever you look at their products and, having heard such great things about them over the years, I really wanted to get the opportunity to find out for myself what the excitement is all about. Devialet began in 2007, set up by three friends; engineer Pierre-Emmanuel Calmel, entrepreneur Quentin Sannié, and designer Emmanuel Nardin. Later it was added to by Franck Lebouchard as CEO. They all had a vision of making a revolution in audio, and with one goal; to make it possible for large numbers of people to be able to listen to perfectly produced music using everyday sound devices. In order to meet their objective this Paris based company has registered over 160 patents covering many different areas of sound construction. Their Expert 220 Pro is just one of a series of very clever fully integrated amplifiers using Devialet’s own operating system based a Linux kernel. It is rated at 220WRMS (at under 6Ω) or can be bridged with a second machine to give 440WRMS. Their top Expert 250 Pro can be bridged to go from 250W to 1000W.

CONSTRUCTION

The laptop-sized/shaped Devialet is pure chromed heaven and includes a circular OLED display screen on its shiny top panel, the whole looking not too dissimilar to my bathroom scales, though significantly more expensive and more useful.  The rear includes a plethora of connections and facilities including Wi-Fi and Ethernet via the AIR app for Mac and Windows (see later), asynchronous USB, S/PDIF and Toslink, RCA, which can be configured as line-level or phono inputs, and a further pair of RCAs that can be either L/R analogue or a pair of digital inputs. Access to the sockets is by sliding off the rear of the top panel and then replacing it after your pluggery to hide the unsightly plugs and cables; a clever idea. The digital inputs support PCM signals up to 24-bit/192kHz (AIR® universal streamer, UPnP, AES/EBU, Coaxial), Toslink 24-bit/96kHz, USB input handling up to PCM 32/192, and DSD64 from USB and coax inputs.  All operation is through a Devialet designed operating system built on a Linux kernel with an ARM 1GHz Quadcore Processor (Freescale iMX6), 1GB of DDR3-RAM and 4GB of Flash memory. The fact that all analogue sources go through an ADC before being processed and then returned as with the digital sources to analogue before working their way to your speakers impressed me, as the sound from my analogue sources during my evaluation showed no sign of lacking musicality or depth of reality as can be the case from digital processing.

This is quite a monster of an integrated in shiny chromed aluminium clothing. It even comes with a pair of white gloves so that you don’t get your fingerprints on the lovely chrome. The only control is the tear-drop shaped on/off button at the front with visuals from a circular display panel on the top. The rear is festooned with the programmable analogue and digital sockets. Only omitted are balanced analogue XLR inputs, though there wasn’t much space for them! It also comes with the most original and beautiful remote there is out there, which is as unique to Devialet as the design of the Pro itself. Carved out of a single aluminium block, the Expert Pro Remote is both very responsive and precise, using as it does zero latency radio transmission technology, and being fully omnidirectional means you don’t need to pick it up and point it at the amplifier. I only wish that it had a LCD display – as the idea of a remote is to sit and be lazy on your chair but should you actually wish to change source and need to see if you have selected correctly you will need to get up and view the display on the top of the main unit, which defeats the object of a remote. However, of course this might be a ploy to persuade you to actually get up and view and adore the beautiful shape and shiny chromed aluminium top; this unit is simply too gorgeous for you to be sitting away on your armchair, nor should the unit be hidden away in a shelf. Certain functions can be altered via the LCD display, such as treble, bass and balance, but can only be done with the remote in hand.

If one 220 isn’t enough for you, you can join two together in dual mono to create effectively an Expert 440 Pro, achieving no less than 2 x 440 Watts of power, should you need it, as well as an improved performance (You can actually daisy-chain up to 8 amplifiers, should you own a stadium). Streaming services also permit UPnP, Airplay®, Roon and Spotify Connect, though for my review I used sources I was familiar with; notably laptop and DAP, SACD/CD and phono.

Inside the Devialet is where all the fun lies. It all started in 2004 with the development of ADH, a hybrid technology embracing both Class A and D technologies in a single unit. The aim was to give the best of both worlds; the musicality and linearity of the Class A voltage amp with all the power and efficiency of the class D current amplification.  It also allowed the unit to be compact with no need for massive toroidal power supplies, coming as it does with a built-in special switch-mode power supply to take you from absolute silence to loud dynamics instantly. This power supply also has a very high-efficiency rate of about 90%. The 220 Pro uses the 2nd version of ADH, the ADHV2®. The class A amplifier – directly connected to the speaker – drives the output voltage, and as the master, it sets the sound of the whole ADH core. The Class D amp, or rather several Class D amplifiers, are added in parallel to provide the speaker with the current it requires and acts as slaves to the master class A amplifier. The Class A section also needs to be able to output a high current over a short period of time and absorb the ripple current of the other amplifiers. The Class A section basically supports the Class D amplifiers and is freed from the task of delivering lots of power. According to Devialet the Class A is improved by the presence of the class D amplifiers in the ADH architecture and in my testing I did find the amplifier very open and musical, as I would expect a Class A, and fast and precise as I would switch mode and class D designs. I was able to listen for considerable periods without fatigue, something I cannot always say with Class D with switch mode supplies. Indeed, Devialet found the Class A amplifier works even better with the aid of the Class D section, something I would have to agree with. At loud volumes, the sound was quick and detailed with exceptionally low distortion levels.

Ahead of the ADH amplification stage is the “Magic Wire” DAC. This is placed before the first amplification stage in order to reduce noise and distortion, utilising the very able Texas Instruments PCM1792 chip. The design enables Devialet to ensure the world’s shortest path between the DAC and speaker connections of just 5 cm and what they refer to as the dream of every audiophile: “a straight wire with gain”, that famous phrase first instigated by Harman Kardon with their Citation line of electronics.

The most exciting part of the design for me is the Speaker Active Matching (SAM®) section that enables the user to adapt the sound signal to match the specifications of their speaker model. Every speaker sounds different and with different pressure levels. What SAM does is adapt the signal to the characteristics of the speaker you wish to use. Laboratory work carried out by Devialet in their factory enables them to identify sixty or more different parameters per speaker model. The results of this hard work are made possible by the powerful DSP at the heart of each Expert Pro system with an impressively large database of loudspeaker options, now over 800, created by real-time listening to actual speakers. For my review, I selected the Wilson Benesch Vertex speaker as the closest link to my elderly Arc. I could hear different settings do affect the overall sound, and the Vertex was the best setting for my chosen speaker for the review.

Also on offer from Devialet is their AIR® (Asynchronous Intelligent Route) high definition streaming system, enabling the listener to enjoy up to 24 bits / 192 kHz via Ethernet or Wi-Fi, regardless of the format, multimedia player or streaming service. Setting up for your designated phono-stage is equally advanced. Thanks to RAM® (Record Active Matching) technology, your phono stage can be programmed not only to select either MM or MC, but one can also alter load impedance and capacitance to concur with your chosen cartridge as well as different equalisation curves, adding up to over 250 combinations.

Programming of all the parameters including those discussed above is very easily done from their website (see accompanying screenshots). Once you have selected/created your profile (I created one called “HifiPig”, surprise surprise) you can save it by right-clicking and selecting “Save Target as” in order to save your personal settings as file dp_cfg.txt (for windows users). Unfortunately, Chrome doesn’t give you this option, so I had to use IE for the first time! Oh, and the SD card is supplied by Devialet and plugs into the rear of the unit once you have set it up as you wish.

SOUND QUALITY

This is an exceptionally quiet amplifier whatever source is selected. Only when using the phono-stage did I ever hear any noise, though that is to be expected. All sources go through a choice of 24bit/96kHz or 24bit/192kHz digital stage, the heart or “intelligence” of the Pro as they refer to it, though at no time in my listening did I even consider this could degrade the sound. First listening was digital via the excellent Krell KPS20i CD player. Vincent Belanger “Pure Cello” is a beautiful CD, produced by Audio Note. This was an engaging performance. The solo cello playing was a positive and forceful performance without being over-powering or tiring. Indeed, all analogue sources I connected into the line input gave a positive performance in terms of accuracy of sound and covering all frequencies with a flat response. Listening to ‘Live at the Citadel’ from my friends The Enid was deep in bass yet top frequencies were equally detailed and clean, with a good sense of being there in the audience. I originally heard the band in the 1970’s and fell in love with the references to Rachmaninov in much of the music as well as the use of synthesiser. The soundstage was large and detailed, without sounding clinical. Listening to sources via USB and SPDif was equally detailed and spacious giving some of the best performances whether FLAC, WAV or DSD. Pat Metheny ‘The Way Up’ and the second track confusingly named “Part One” had a great top end and bass that was relaxed but authoritative. Similarly, Muse Resistance album and “Uprising” has a deep bass at the start which was clean and clinical, though no less enjoyable. Listening to Supertramp ‘Breakfast in America’ on CD the sound was noticeably digitised than when I play my vinyl version of the album. Interestingly, playing it from vinyl, which still goes through a 24/192 ADC, sounded superior.  The Devialet performed well in all I played, whether analogue or digital, though vocals and mid-frequencies were more forward in the presentation. Indeed, whilst the Expert 220 Pro worked great with all types of music and instrumentation my only slight concerns as a critical reviewer was a very slight sibilance with some vocals (mainly female), and the sound lacking some warmth in performance.

Feeding via USB from my notebook music was quick and precise with a good grip on detail and fast initial transients, just lacking that warmth I would like to hear. Turning to Vinyl was the biggest surprise for me. Bearing in mind all sources end up going through an ADC, the sound was particularly well defined and pleasurable after I matched ohms and microfarads. Devialet claims this to be the world’s most advanced phono-stage, and for an integrated ten pounds short of £7000 with built-in phono-stage plus DAC and streamer, it was powerfully impressive. Listening to the 25^th David Bowie album released two days before his untimely death from Liver cancer, “Legacy”, this album contains many of the Tony Visconti produced technicalities that I never feel sound good on Hifi, though are very effective in what they are trying to convey. This phono-stage gave a musical and defined performance offering a good insight into the top frequencies and with good bass extension. After this was my chance to listen to an album kindly supplied and produced by Devialet, part of a legacy of lost recordings put together jointly with Fondamenta from a selection of great artists such as Art Blakey, Dizzy Gillespie, Oscar Peterson, Thelonious Monk, and my hero Dave Brubeck. These are a series of recordings “on the verge of extinction” and using cutting edge technologies bringing them back to life. The Dave Brubeck Quartet’s ‘Live at the Kurhaus’ album recorded on 24^th October 1967 was particularly enjoyable since this includes my favourite track “Forty Days”, beautifully produced later in ‘A Cut Above’ with his sons playing. This track is almost an oratorio, featuring biblical references and themes from the great blockbusters. Whilst stereo-spread was rather lacking in this recording, it was nonetheless a memorable performance and production, and jazz fans should look out for these beautifully produced and limited-edition LPs and CDs, restoring the performances using Fondamenta’s unique Phoenix Mastering® technology. Turning to Dire Straits live ‘Alchemy’ album I could really start to take in the extremes in frequency and dynamic attributes; this album does them all. Lots of bass drum and high-frequency synthesiser, plus everything in between including audience noises. Always a good album to play in reviews as it can often sound a bit contrite in performance if in the hands of the wrong gear. Whilst this phono-stage coped admirably I felt the sound was just a tad too clinical, again lacking some three-dimensionality, and I preferred my choice phono amplifier though that is much more expensive. “Private Investigation” had a larger soundstage, especially with the guitar riffs, but everything was just too tidy for me. That said, as part of an integrated, and a very clever one at that, it was one of the best phono-stages I have heard. I altered the phono R/C and settings to get a slightly better bass end, though doing so meant I needed to switch off and get back on my computer. Playing my favourite Beethoven piano concerto (The Emperor Concerto No5, Zubin Mehta/Israel Philharmonic Orchestra, DECCA) the sound had a grand bass and excellent soundstage showing the phono-stage working well and effortlessly on all types of music. The performance from this 1979 recording of his last piano concerto was well balanced from all instruments, with the amplifier having enough welly in reserve if I ever needed it, particularly when the piano fortissimos warranted it. Detail from piano mechanics in trills in the second movement gave the performance some needed realism making the performance more engrossing.

I listened to a considerable amount of music for this review as I really wanted to get a good insight as to musical qualities and technicalities of this unit. The soundstage was large as I would expect with lots of details on midrange and above. Having said that, the bass was full but not as decisive as I would like. The detail in the portrayal of the music means that if your music had any faults then it would show them off; something as a sound-engineer I really like. Some might, however, find the sound just a little too perfect and clinical, and lacking some depth and warmth.

CONCLUSION

This is a highly original adventure in integrated audio design. The price might not be as low as some integrated amplifiers out there but let’s look at the evidence; a beautiful construction and design including that lovely remote, a built-in DAC, Phono stage, Wi-Fi and ethernet. It recreates music with a clarity and transparency that surpasses many out there, perhaps only just sounding a little clinical to some listeners. However, I was still highly impressed, and it is well worth having a listen to, as well as a looking at.

AT A GLANCE

Build Quality: Beautifully constructed and gorgeous looks

Sound Quality:  Fatigue-free listening with an accurate presentation of all frequencies, and excellent noise floor. Distinctive Devialet signature sound

Value for Money: £6,990 is very good value when you consider what it can do. 

Pros:

Advanced design and capabilities

Detailed coverage from lows to highs

Fatigue-free

Lovely remote with large knob puts others to shame

Cons:

Some might find sound too clinical

Slight sibilance in vocals/mids if they are overbearing

Price: £6990

Janine Elliot

Review Equipment:

Krell KPS20i CD, Pre-Audio turntable/AT33sa cartridge, PC FLAC/DSD files, Wilson Benesch Arc/Torus speakers with Townshend Supertweeter

Specification

PERFORMANCE

• Power : 2x220WRMS 6Ω
• Signal-to-Noise ratio : 130dB
• THD – 130W/6Ω : 0,0005% / -106dB
• THD – 10W/6Ω : 0,00025% / -112dB
• Output impedance : 0,001Ω
• Damping factor : 8000
• Thermal distortion : Below measurement threshold
• Technologies : ADHV2®, SAM®, AIR®, EVO®, DAC Magic Wire®, RAM®

PHONO STAGE

• Type of supported cartridges: MM/MC
• MM sensitivity from 1mVRMS to 15mVRMS
• MC sensitivity from 100 μVRMS to 5000 μVRMS
• 256 combinations for the resistive/capacitive loading of the cartridge
• Stereo/mono/left/right mixing
• 13 equalisation curves available
• Specific menu for dynamic adjustment of all these settings

PREAMPLIFIER & MAIN DAC

• Patented Magic Wire Digital / Analogue Converter, D/A T.I. PCM1792
• Unique high-precision Master Clock with very low jitter: 2ps rms
• Conversion of all inputs into 24-bit/192 kHz
• Built-in DSD / PCM conversion
• SAM profile via configurator allowing the precise adaptation of the sound signal to the specifications of your speakers
• Available active filtering on all analogue outputs via configurator
• Volume control in increments of 0.5 dB
• Volume adjustment range: -97.5 dB to +30.0 dB
• Bypass/pass-thru mode available input by input
• Balance adjustment
• Tone control: bass +/-18 dB, treble +/-18 dB with variable frequency cut-off via configurator

GENERAL

• Finish: Chassis carved out of a single aluminium block
• Colour: Dark chrome finish
• Dimensions: Length: 383mm | Width: 383mm | Height: 40mm
• Weight: 5,9Kg
• Installation: Horizontal or vertical installation with automatic tilt detection
• Synchronisation: Up to 8 units