Devialet D-Premier D/A integrated amplifier Phono Stage

John Atkinson returned to the D-Premier in June 2013 (Vol.36 No.6):

When I reviewed this extraordinary French amplifier last January ($15,995), I ran out of space and time before I could audition and measure its performance via its phono inputs. That is the subject of this Follow-Up. My sample of the D-Premier was serial no.00965, hardware v.4.1.1, running firmware v.5.6.0.

Fig.1 The Configurator widget on the Devialet website allows the D-Premier's owner to create a custom configuration text file that can be downloaded.

Like almost all of the D-Premier's input and output jacks, the two RCAs used for the first line-level input can be reassigned in software to handle phono signals. You visit the Configurator page on the Devialet website and, using the interactive illustration of the D-Premier's rear panel (fig.1), customize the input to suit your LP player.

Fig.2 The set-up page for the Devialet D-Premier's phono stage offers many options.

The options are: moving-coil or moving-magnet, each with ranges of gains and capacitive and resistive loadings; stereo or mono; L/R balance; 1953 or 1976 startup RIAA curve; and a sample rate of 96 or 192kHz (fig.2). (The D-Premier digitizes its phono inputs and applies the RIAA de-emphasis in the digital domain.) Once the options have been chosen, the website widget creates a text file, dp_cfg.txt, which can be downloaded and copied to an SD card that slots into the D-Premier's rear panel. When you next turn the amplifier on, it reads the text file and reassigns its inputs accordingly; as it does so, it shows on its top-panel display the message "Custom Config."

To test the phono stage, I set the D-Premier's third pair of RCA jacks to be either a fixed-level pair of analog outputs, or one of the jacks to be a fixed-level S/PDIF output. (Both outputs can also be variable level, adjusted with the remote control's volume knob; the S/PDIF sample rate needs to be set independently of the A/D converter's sample rate.) I examined the phono stages in both the analog and digital domains using Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It").

To choose the gain appropriate for your cartridge, you move the Max Level slider on the Configurator. For MM, setting this to "5.0mV" gave a measured gain at the Preamp output jacks of 45.3dB (45dB is specified); setting it to "10.0mV" gave 39.5dB (39dB specified). For MC, setting this to "500µV" gave a measured gain of 62.5dB. Which gain you choose will be critical, as you need to avoid overloading the D-Premier's A/D converter. With the MM input set to "5.0mV," a 1kHz tone at 5mV resulted in a digital-domain signal at –2.18dBFS. For my Linn Arkiv B MC cartridge, I had to set the Max Level to "1500µV"; with typical LPs, this resulted in digital peaks of around –3dBFS.

The D-Premier's phono input preserved absolute polarity (ie, was non-inverting) in both MM and MC modes. Set to MC, the highest choice of input impedance was 460 ohms; I measured 461 ohms. In MM mode, the highest input impedance is unhelpfully called "High." I measured 14k ohms at 20Hz and 1kHz, dropping slightly to 12k ohms at 20kHz. This might bit too low for Shure cartridges, which like to see 68k ohms.

Fig.3 Devialet D-Premier phono stage, response with RIAA correction, 192kHz sampling, measured at analog Preamp outputs (left channel blue, right red; 1dB/vertical div.).

Fig.3 shows the D-Premier's RIAA error, set to 192kHz sampling and the 1953 curve. The channels are superbly well matched, and the de-emphasis is perfect up to 10kHz, better even that that of the Liberty B2B-1, which was the best I had measured until now. The level at the preamp outputs then starts to roll off, reaching –1dB at 20kHz and –6dB at 50kHz. To my surprise, changing the sample rate to 96kHz gave the same result from the analog outputs, without the expected brick wall at 48kHz. Changing the RIAA curve to "1976," which I had assumed would apply the specified high-pass rolloff of –3dB at 20Hz also made no change in the measured response. Perhaps the 1976 revision of the RIAA curve will be implemented in a future firmware release.

Fig.4 Devialet D-Premier phono stage, MM mode, digital-domain spectrum of 1kHz sinewave, DC–50kHz, at 5mV input and 96kHz sampling (left channel blue, right red; linear frequency scale).

Fig.5 Devialet D-Premier phono stage, MM mode, digital-domain spectrum of 19+20kHz sinewaves, DC–50kHz, at 5mV input (after pre-emphasis) and 96kHz sampling (linear frequency scale).

Channel separation (not shown) was good, at >80dB below 1kHz, and noise was very low in MM and MC modes. The overload margin was good, at an even 17dB across the audioband in MC mode (set to "500µV") and 20dB in MM mode (set to "10.0mV"). One peculiarity: At 20kHz, some sort of soft limiting seemed to be in effect; I couldn't get the input to overload. Distortion was low, at typically 0.06%, and dominated by the subjectively benign second harmonic (fig.4), though this digital-domain spectrum does reveal some low-level, higher-order harmonics. Intermodulation distortion was also low (fig.5).

As well as auditioning the D-Premier's phono stage, using my usual Linn analog front end of Sondek LP12 turntable, Ekos tonearm, and Arkiv B cartridge, I used the amplifier to rip some LPs, using its digital output to feed the S/PDIF input of a Metric Halo ULN-2 FireWire interface and recording the data as AIFF files on my MacBook Pro. Perhaps I endanger my Audiophile Reviewer badge by admitting this, but I could hear no substantive difference between the D-Premier's phono stage set to sample at 96kHz or at 192kHz when playing LPs. Because the Metric Halo will accept data up to only 96kHz, that's the rate at which I performed my rips. However, I did check that the D-Premier's digital output correctly output data at 192kHz by connecting it to the Audio Precision's S/PDIF input. This also allowed me to confirm that all 24 bits in the Devialet's digital output are active.

As for the sound of the D-Premier when used to play LPs, it was clean, clean, clean—not in the sense of sterile, but in the sense that there was very little coming between the music and me. There was a delightful delicacy to Radka Toneef's fragile soprano in Jimmy Webb's "The Moon Is a Harsh Mistress," from her Fairytales (Odin LP03), yet with clarity and weight given to the accompanying acoustic piano. In "Die Tänzerin," from Ulla Meinecke's Wenn Schon Nicht für Immer, dann Wenigstens für Ewig (German RCA 426124), the absence of grunge let me hear the decaying reverberation of her voice at the end of each phrase with a clarity I had not experienced before. Back in the day, I used to time how long I could hear the decay of the reverb, and it was the rare playback system that let me get past 2 seconds or so. The Devialet's resolution and low noise revealed a full 3 seconds' worth of reverberation.

The inevitable ticks and pops on my old LPs also seemed more tidily handled, less sonically obtrusive, by the D-Premier than by a conventional analog phono preamp, the Liberty B2B-1, feeding the Ayre Acoustics QA-9 A/D converter, which I reviewed last November.

The Devialet D-Premier's phono stage sounds and measures up to the superb standard set by the amplifier's performance with line-level analog and digital signals. As I write these words, the UPS man is on his way to pick up the D-Premier to return it to the distributor. I'm already missing it!—John Atkinson

COMPANY INFO
Devialet SAS
US distributor: Audio Plus Services
156 Lawrence Paquette Industrial Drive
Champlain, NY 12919
(800) 663-9352
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COMMENTS
mphatic1's picture

John,

 

In your opinion, how does the Devialet's pre-amp/DAC section stack up against the Classe CP-800?  I ask this because they both appear to be cut from the same cloth so to speak; beautifully styled, apparent 18 bit resolution, switching amp/power supply, highly configurable, and relatively future proof.  And, when you start to add power amps to the CP-800, you get up around Devialet money anyway.

 

Regards,

Brad

JadenKrosis's picture

"the most extraordinary product I have reviewed for Stereophile."

Considering the very long list of other very extraordinary products you`ve had your hands on, this says alot!

rumnyc's picture

but in the end went with a slightly more conventional setup.

for exactly the same price as a D-Premier, I went with a Linn Akurate DSM and Mcintosh MC452 amp. I couldn't compare them back to back but I like the below features from the Linn:

4 HDMI input instead of 1 (yes I could have used an outboard HDMI switcher).

Ethernet input and DLNA server compatible (AIR feature was not yet released)

And the Mcintosh had way more headroom than the D Premier's amp.

My speakers are B&W 802 Diamond.

stgomes's picture

 

After some very good 1st impressions on sound quality driving "conventional" speakers (impedance curve not bellow 2-3 Ohm) I was curious to audition the D-Premier with my Martin Logan Summit X speakers. Sound quality is very good, until I pumped up the volume. At about 85db, the protection LED on the front panel starts blinking and the amp starts to mute.

I have reported this problem to Devialet and they say it should not happen, but my dealer had the same experience with other D-Premier units driving other Martin Logan models (Montis, Spire, CLX).

My guess is that this amp technology is simply not designed to drive impedance loads like the ones present in Martin Logan speakers, which drop bellow 1 Ohm in the high frequencies.

Looking forward to your comments.

John Atkinson's picture

Quote:
My guess is that this amp technology is simply not designed to drive impedance loads like the ones present in Martin Logan speakers, which drop bellow 1 Ohm in the high frequencies.

That's what I expect, too.

John Atkinson

Editor, Stereophile

BradleyP's picture

Notice that with the new SAM technology, two Martin Logan speakers have been matched to the Devialet--the Theos and the Electromotion. Now, I am wondering about Maggies. If Devialet can both drive and tame those big bass panels, then that would be even more amazing.

jlesnick's picture

Hey John.

Thanks for this great review. How do you feel the Devialet (and its new iteration) would stack up to a Pass X250.5/Classe Cp-800 combo?

Cheers,

Jon

John Atkinson's picture
jlesnicj wrote:
Thanks for this great review.

You're welcome.

jlesnicj wrote:
How do you feel the Devialet (and its new iteration) would stack up to a Pass X250.5/Classe Cp-800 combo?

I haven't heard the XA20.5 but the Pass XA60.5s have been my go-to amplifiers for the past year. The beauty of the Devialet is that it is just one box, with a digital section up there with the Classe. A review of one of the less-expensive Devialets is in progress.

John Atkinson
Editor, Stereophile

bapcha's picture

JA/Other reviewers:

You guys are a prime example of promoters of peddlers of snake oil. If an Airport (Mac) or a Ayre CD player feeds data to a D/A you claim to hear a difference. How can you - when the data is exactly the same?

Let's take Boulder - I like the look of their products, but how would a volume knob - polished seven times and clear-coated - improve sound quality? It is a bloody waste of money.

Cheers,
Bapcha (yes, I am a marketer who can see through your ____)

John Atkinson's picture
bapcha wrote:
You guys are a prime example of promoters of peddlers of snake oil.

Good morning to you, too.

bapcha wrote:
If an Airport (Mac) or a Ayre CD player feeds data to a D/A you claim to hear a difference. How can you - when the data is exactly the same?

Yes, the data may be the same, but the timing of when those data are presented to the D/A chip is also important. Variations in that timing are called "jitter" and result in distortion in the reconstructed analog signal. The right data at the wrong time is equivalent to the wrong data. There are several articles on this subject reprinted in our free on-line archives.

bapcha wrote:
Let's take Boulder - I like the look of their products, but how would a volume knob - polished seven times and clear-coated - improve sound quality?

No-one has said that it does.

John Atkinson
Editor, Stereophile

bapcha's picture

I will keep the conversation very respectful. I am a chip designer with ten plus years designing analog and digital chips and, and ten more marketing them and SSDs. Four issued patents (primary author). Most chips now have PLLs. After it locks, it does not matter if the jitter is 5 pico seconds or 50 pico seconds, the data can be PERFECTLY reconstructed (or the designer will lose his job, and chip cannot be sold).

You claim to hear differences in jitter between 5ps and 50ps - when the data is PERFECTLY reconstructed post-jitter.

YES - you can hear a difference in ANALOG products. If a DAC has a DIFFERENT analog output, it will sound different from a cheaper one with a not so well designed output.

Also, FYI, it is easier to match currents on chips without trying too hard (it is called a common-centroid layout where transistors are laid our perfectly symmetrically (x and y axes). It is not too hard to make chip-based output stages that sound better than discrete (but it is cost-prohibitive). I own Bryston/Ayre stuff with properly designed circuits, and sincerely believe it is impossible to do better (note the word impossible).

I have collected serial data from a $10K Boulder DAC and a $1000 Bryston Dac. I gave up after 10 GigaBytes. The data was exactly the same. So, 24x oversampling = 4x oversampling = 2x oversampling (I know that you know the Nyquist-Shannon theorem). It is a fool's game after one gets past the Bryston/Ayre A* (not the K*) price point.

Word length matters. Sampling rate does not. If it does, then I have a TV that shows pictures in X-ray.

Even James Tanner of Bryston has admitted that the differences between their BP10/17/26/SP3/SP2 analog stages are identical or have minuscule (inaudible) differences.

Bottom-line: Looks like I am half way agreeing with you and half-way disagreeing with you.

Sincerely yours,
Bapcha

John Atkinson's picture
bapcha wrote:
I am a chip designer with ten plus years designing analog and digital chips and, and ten more marketing them and SSDs. Four issued patents (primary author). Most chips now have PLLs. After it locks, it does not matter if the jitter is 5 pico seconds or 50 pico seconds, the data can be PERFECTLY reconstructed (or the designer will lose his job, and chip cannot be sold).

An impressive resume. So with respect, I am puzzled that when you refer to phase-locked loops (PLLs), you don't seem aware that a PLL circuit has a corner frequency, below which it increasingly fails to eliminate jitter in the incoming datastream. You can see the effects of this problem in the various digital products that I test for for Stereophile. Some are very effective at eliminating the effects of datastream jitter; others are wide-open to timing variations in the data presented to the DAC.

bapcha wrote:
You claim to hear differences in jitter between 5ps and 50ps . . .

We have made no such claim, any more than we have claimed, as you accused us in your earlier comment, that the finish of the volume control on a Boulder preamplifier affects sound quality.

John Atkinson
Editor, Stereophile

bapcha's picture

Thanks for your kind and timely responses.

Bottom-line: JA - we all have our biases. Bottom-line is the you run the best publication for reviews of music reproduction electronics. Today, a Cisco router can transmit ALL of the data from the Library of Congress from point to point - in about four seconds. Yet - there is room for endless back and forth for a trivial range of frequencies. Let's call it 0 Hz to 100KHz. When we have mastered 10s of gigahertz, we should be able to do this trivial range in frequencies easily, cheaply, perfectly, every single time - and yet we don't. My take is that it is due to the EMOTIONAL component of this trivial data "band" if you may.

I wish you and your magazine the best. (I know Robert Greene rather well. He is a colleague of my uncle's at UCLA math)

John Atkinson's picture
bapcha wrote:
Bottom-line is the you run the best publication for reviews of music reproduction electronics.

Thank you.

bapcha wrote:
Today, a Cisco router can transmit ALL of the data from the Library of Congress from point to point - in about four seconds. Yet - there is room for endless back and forth for a trivial range of frequencies. Let's call it 0 Hz to 100KHz. When we have mastered 10s of gigahertz, we should be able to do this trivial range in frequencies easily, cheaply, perfectly, every single time - and yet we don't.

That the transmission of digital data without errors is a given. But it is when those data are used to reconstruct an analog signal that problems in implementation arise.

bapcha wrote:
I wish you and your magazine the best. (I know Robert Greene rather well. He is a colleague of my uncle's at UCLA math)

Thank you. But I am wondering if you are confusing Stereophile with The Absolute Sound. Robert Greene writes for TAS, and has never contributed to Stereophile.

John Atkinson
Editor, Stereophile

bapcha's picture

Nice guy anyway. Took him a long time to switch to digital, and solid state.....

Sincerely,
Bapcha

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