Review: Devialet Expert 220 Pro

The sound is as one would expect from a massive monster amplifier. Powerful, dynamic and vibrant, almost physical, and with extreme goosebumps. But there is no monster amplifier in the room. Instead, it is barely visible from the couch.
Even the remote control is not as expected. Like the amplifier itself, it is minimalist, shiny and carved out of a piece of aluminum.

It is so elegantly executed, and at the same time so eccentric, that it can only be French.
Devialet took us big when they debuted with a bang in 2011, with D-Premier. The ancestor of the Expert Pro 220, which we test here. Since 2011, the engineers at Devialet have been true to the basic concept, but refined it in several stages until the current generation of Devialet amplifiers.

Which is not like other amplifiers. Neither outside nor inside.
There are no cooling fins, handles or potmeters here. No button rows, Vu meters or modules. Just a polished surface on a toad-flat cabinet. As you can barely see from the sofa. The amplifier is a number more powerful and better equipped than the entrance ticket to Devialet, Expert Pro 140.

ADH amplifier

Inside we find the same technique with ADH (Analog-Digital Hybrid) which combines an analog class A amplifier stage, which supplies the voltage to the speakers, with a digital (class D) amplifier stage which supplies power to the speakers.

Devialet says that they have managed to lower the distortion further in 220 compared to the previous generation Expert Pro, and at the same time increased the power to 220 w – in 6 ohms, compared to Expert Pro 140. That is not all. In a 220 you get a couple of extra RCA inputs for either analog stereo sound, or two digital inputs. It also has balanced digital input, a more advanced phono stage for MM and MC pickups, with multiple customization options and hundreds of pickups housed in a database.

RAM and SAM

The amplifier also has SAM (Speaker Active Matching), which can be inserted into the amplifier as a configuration, and like the phono stage RAM (Record Active Matching) which is adapted to a selected pickup, the speaker data is fed into the amplifier with a memory card. RAM and SAM are activated in the configurator that you need online to use. Log in to Devialet’s website, enter the serial number of the amplifier, and go to the configurator. There you can configure the inputs as you want, search for the pickup in the RAM database, and download SAM data if they are available for the speaker you have.

When the memory card is inserted back into the amplifier, the new configuration is inserted into the amplifier. When later selecting the turntable input, the phono step will be adapted to the selection of the pickup’s output voltage, load impedance and RIAA characteristics.

The analog signal from the pickup thus passes through the preferred RIAA curve and 24-bit, 192 kHz signal processing, with absolutely zero noise.

With SAM, the speakers’ impedance curve, frequency response and deviation between the speakers are adjusted, with the result that a small bookshelf speaker suddenly goes much deeper in the bass, and that a selected speaker pair gets almost perfect timing between right and left channel.

Another effect of SAM is that the bass element’s stroke length is no longer challenged when playing very loud. The compensation filter in the SAM file also monitors the movements of the bass element in real time, and protects against flashes.
There are over 800 speaker pairs in Devialet’s database, and more will be added over time.

Streaming, or AIR as it is also called

The Devialet Expert 220 Pro, like all Devialet amplifiers, is equipped with AIR, which is an engineering abbreviation for Asynchronous Intelligent Route. You can stream to a 220, either over the network via Ethernet or wirelessly with Wi-fi directly, up to 24-bit and 192 kHz quality. A music library connected to the network, Spotify straight from the mobile, Tidal Masters from the laptop or a Roon client, everything works with an Expert Pro, which also supports bitperfect for better sound.
There is an app for selecting the source and managing an Expert Pro, but compared to e.g. Naim’s app, it’s pretty scratchy for setting options, but if you have a Roon subscription you get a better overview and control of a 220 via mobile.

Heavenly revelation

It does not take long before you realize that it is not just the design and technology that is special about a Devialet amplifier. The sound quality of what comes out of the speakers can make even reputable muscle enhancers blush. The small Devialet amplifier is able to challenge all amplifiers we have tested in the price range up to at least NOK 100,000.
Here you not only get a power amplifier with DAC and phono steps, you also get sound in a class that goes far beyond most we have tested. The question is whether there is a more complete and well-sounding amplifier for the price at all.

It played with Vivid Audios Kaya 90 in the test of Geir Gråbein, and the joy of playing was overwhelming together with Audiovector’s fantastic R3 Arreté. The compact favorite speaker and our price range reference, the Dynaudio Special Forty, sounded a few notches bigger along with the Expert Pro 220, when SAM was active. and the fine hybrid electrostats from Martin Logan – Electromotion ESL X, got real deep bass along with the 220.

This is what the result looks like when a Martin Logan ESL X is configured in SAM.There are more powerful amplifiers out there, McIntosh MA9000 and Gryphon Diablo 300 for example, and there is a warmer and more refined sound in an Audio Research GSi 75, but the Devialet amplifier’s trump card is in the speaker adaptation, which for many is perhaps the most weighty reason for to choose just an Expert Pro.

Strings like the overture to Puccini’s La Boheme sound powerful and refined at the same time. When it is pressed into the orchestra pit, you feel it in your stomach. The amplifier does not hold anything back. I have never heard the easy-to-drive Audiovector speakers better, and the bass reproduction on Electromotion enchants the basses in the orchestra. A subwoofer could hardly have done better.

But it is the relaxed, natural and organic flow in the music that is reminiscent of a hybrid between a well-designed tube amplifier and a muscular MosFet amplifier that is so seductive. The slightly shrill piano sound at Keith Jarrett’s Cologne concerto is clearly visible in the soundscape, but the concert hall seems larger, at the same time as you move a little closer to the edge of the stage, compared to e.g. McIntosh MA7200. Which is in the same price range.

The McIntosh amplifier sounds fuller, even in the bass, and it has better dynamic control. But that is only until SAM is activated from the remote control. Then the bass becomes tighter in the 220, it goes deeper and the dynamic contrast is audibly better. The Phono step is also better in the 220, and both our Audio-Technica AT-OC9XSH and an Orthophon Cadenza Bronze, sounded faster, more open and more focused with the Devial.

On the aforementioned La Boheme, I preferred the vocal sound of the McIntosh amplifier. The same was true for such different voices as Bob Dylan and Khalid, while Kari Bremne’s bell-ready voice sounded better defined with the 220.

Conclusion

The Devialet amplifier moves the music three rows closer to the listener, and reproduces the acoustics of the recording with outstanding precision. It has total control from deep bass to treble, until it is pushed beyond capacity. Then the dynamics are held back a bit and the amplifier struggles a bit to hold the grip. Should you need even more power than a 220 can deliver, you can buy a so-called Companion amplifier. An extra amplifier that when connected to the 220 you have, doubles the power and halves the distortion, and upgrades the sound in the system even more notches. Most of us will manage for a long time with one Expert Pro 220, which we do not hesitate to call the most complete high-end amplifier in its class.