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Devialet Expert 200 Amplifier, DAC and Streamer Review

GXAlan

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The noise floor no longer has that rising trend.

Interesting that it was fixed with no note. For all the negative comments, it is commendable that they covered an out of warranty repair for a non-original owner. I am sure being on ASR helped, but Devialet at least has tried to offer good customer service when it comes to replacing things (and less effective customer service in listening to customer software requests).

@BDWoody
Why don’t you ship all those old Denon receivers to amirm and then raffle the good ones off to readers and donate the “bad” ones to Goodwill/Salvation Army? Better than having it stuck in the attic and if they are that old, they may not be worth much.
 

QMuse

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The noise floor no longer has that rising trend.

Interesting that it was fixed with no note. For all the negative comments, it is commendable that they covered an out of warranty repair for a non-original owner. I am sure being on ASR helped, but Devialet at least has tried to offer good customer service when it comes to replacing things (and less effective customer service in listening to customer software requests).

Do you think they would do the same for any other customer or this was just a damage control as poor performance was published publicly on this forum?
 

GXAlan

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Do you think they would do the same for any other customer or this was just a damage control as poor performance was published publicly on this forum?

There are several “zero watt” phantoms that were replaced outside of warranty and a lot of “cracked” phantoms that were also replaced out of warranty. All were part of message board discussions, but none by reviewers.

But, you won’t find a happy owner of a Phantom when it comes to software...
 

QMuse

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There are several “zero watt” phantoms that were replaced outside of warranty and a lot of “cracked” phantoms that were also replaced out of warranty. All were part of message board discussions, but none by reviewers.

But, you won’t find a happy owner of a Phantom when it comes to software...

Judging by the dashboard of a repaired one I wouldn't expect too many happy owners with the hardware as well. Except for the ones that don't understand they've paid a lot of money for a below par product.
 

MZKM

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With this knowledge, I reduced output power to below 1 watt and ran my frequency response sweep:

index.php


This is line-in so is digitized. It produces about 48 kHz of bandwidth
I don’t know if this has been discussed, but the ADC is switchable for 192kHz:
In Devialet Configurator it is under the "Advanced Settings" for the line inputs: When using the digital inputs the audio is processed at the native rate of the media, up to 192kHz.

HiFi World measured the frequency response of an Expert 120 using a 192kHz signal, it was flat to 63kHz and then gently rolls off to 96kHz.

http://absolutesounds.com/pdf/main/press/DV_120_HIFIWorld_NOV2014.pdf
 
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Frank Dernie

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I don’t know if this has been discussed, but the ADC is switchable for 192kHz
It is one of the configurator choices, presumably because some see more=better but it is not the default and not recommended by Devialet as offering zero potential SQ improvement and a possibility of a "wider window" letting in more rubbish.
I did try it on my phono input on the D-Premier 10 years ago on the "more=better" basis but ended up going back to the sensible default.
 

T-NYC

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Lots of interesting stuff here - thanks for posting. When I think of Hirsch, "no bad reviews" isn't what comes to mind. It's more like "these specs, which we've confirmed in our lab, tell you everything you need to know about the Pioneer RCH-2745 solid-state receiver." Which would turn out to sound deadly when you brought it home from the hifi shop.

Holt was different in that he believed in listening as the final arbiter of merit, which was pretty radical at the time. Yes, he was fully conversant with the technical issues that mattered. He just didn't linger on them. I believe Stereophile still expects this of its reviewers, which is why Dudley does SET amps and Atkinson doesn't (though I suspect he knows a fair bit about SETs).

And Holt was a terrific writer - brisk, precise, and drily funny. Much better, as I remember it, than anyone at the other mags of that time. Of course, he thought that component break-in is a real thing!

Any idea where I might read a Heyser review?


Late reply to this, however the myth that audio reviewers before Holt did not listen is only a myth. If you go online and check Audio reviews from the earliest issues through 1975 or so, always there are comments and discussion of sonic qualities, unless the specs told the entire story. This was true even of turntables where extensive disciussion of sonic differences was the norm. However, unlike Holt, who was a well-intentioned PR guy, these were informed discussions.
 

T-NYC

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DEVIALET video. They adapt their amps to more than 800 speakers.

sorry this is late, however SAM is not an engineering advance, but rather a marketing advance. All class D except UcD, Ncore, Eigentakt have significant frequency-related issues. SAM is simply a way for less than stellar class D to maintain flat response regardless of frequency, by making the zigs match the zags. Better to purchase an inherently well-designed amplifier instead of a heavily-bandaged one.
 
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T-NYC

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SET amp manufacturers have been doing that since 1927!
S

A small correction to the SET post in this thread (sorry, this was meant as a reply to that) -- SET died an early death; serious engineering moved on quickly. SET was resurrected by voodoo-practioners (notably in France by non-engineers) in the 1990s. It is popular today because no R&D costs are incurred.
 
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Frank Dernie

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however SAM is not an engineering advance, but rather a marketing advance.
I agree in part, the marketing part, it is good marketing. Engineering wise it is a unique comensation potential for speaker shortcomings but only if you own calibrated speakers they have measured.
The D-Premier was released before SAM, in fact the board updates for the next model were maiinly to add the DSP hardware to allow SAM.
The D-Premier had low output impedance and vanishingly low distortion as well, so SAM has nothing to correct there and only is used to compensate the bass errors in those speakers they have measured and made a file for. The speakers I mainly use have never been measured so my Devialet runs without SAM.
The Devialets are not class-D.
Pruno Putzeys of nCore and Eigentakt fame was apparently impressed by the performance but felt it was overkill and that the same performance could be achieved with a much cheaper and simpler circuit.
 

Soniclife

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All class D except UcD, Ncore, Eigentakt have significant frequency-related issues.
Some have a little HF roll off, none have low frequency issues that I've seen.
SAM is simply a way for less than stellar class D to maintain flat response regardless of frequency, by making the zigs match the zags
You have misunderstood what this is doing, this is nothing to do with correcting the amps frequency response, even the broken version measured here was flat to 48KHz.
 

T-NYC

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I agree in part, the marketing part, it is good marketing. Engineering wise it is a unique comensation potential for speaker shortcomings but only if you own calibrated speakers they have measured.
The D-Premier was released before SAM, in fact the board updates for the next model were maiinly to add the DSP hardware to allow SAM.
The D-Premier had low output impedance and vanishingly low distortion as well, so SAM has nothing to correct there and only is used to compensate the bass errors in those speakers they have measured and made a file for. The speakers I mainly use have never been measured so my Devialet runs without SAM.
The Devialets are not class-D.
Pruno Putzeys of nCore and Eigentakt fame was apparently impressed by the performance but felt it was overkill and that the same performance could be achieved with a much cheaper and simpler circuit.

The D-Premiere was a very good product and a promise of better yet to come. I do not know what went wrong with the company culture to have evolved as it did. The Devialet amp circuit is a current dumper, first patented by Peter Walker of Quad in 1971. A small class A amp provides a quality signal, while a large non-class A amp provides the muscle. The second amp may be of any class except class A. The Devialet uses a class D amp for this stage. Most class D amplifiers, except those I noted, behave with a certain amount of non-linearity depending on frequency / impedence. SAM is as I desciribed, a zig to balance a zag. Bruno is a friend and I assure you was not impressed.
 

T-NYC

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Some have a little HF roll off, none have low frequency issues that I've seen.

You have misunderstood what this is doing, this is nothing to do with correcting the amps frequency response, even the broken version measured here was flat to 48KHz.


Yes into an 8 ohm resistor ;-) If you examine the literature on class D (plenty to be found at AES archives) I believe you will see for yourself that frequency / impedence response irregularity is why they were largely confined to use as subwoofer amps for a long part of class D history. Reminder -- commercial class D amplifiers have been on the market since 1975.
 

Frank Dernie

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The D-Premiere was a very good product and a promise of better yet to come. I do not know what went wrong with the company culture to have evolved as it did. The Devialet amp circuit is a current dumper, first patented by Peter Walker of Quad in 1971. A small class A amp provides a quality signal, while a large non-class A amp provides the muscle. The second amp may be of any class except class A. The Devialet uses a class D amp for this stage. Most class D amplifiers, except those I noted, behave with a certain amount of non-linearity depending on frequency / impedence. SAM is as I desciribed, a zig to balance a zag. Bruno is a friend and I assure you was not impressed.
I am afraid you are quite wrong.
Where on earth did you get this idea from?
I know their chief engineer quite well and I know exactly how it works.
You have picked up a mish mash of typical internet misunderstandings.
It is similar to current dumping but your explanation is in every other way incorrect.
 

Thomas savage

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The D-Premiere was a very good product and a promise of better yet to come. I do not know what went wrong with the company culture to have evolved as it did. The Devialet amp circuit is a current dumper, first patented by Peter Walker of Quad in 1971. A small class A amp provides a quality signal, while a large non-class A amp provides the muscle. The second amp may be of any class except class A. The Devialet uses a class D amp for this stage. Most class D amplifiers, except those I noted, behave with a certain amount of non-linearity depending on frequency / impedence. SAM is as I desciribed, a zig to balance a zag. Bruno is a friend and I assure you was not impressed.
When your really good friends with Bruno you get to call him Pruno .
 

Soniclife

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Yes into an 8 ohm resistor ;-) If you examine the literature on class D (plenty to be found at AES archives) I believe you will see for yourself that frequency / impedence response irregularity is why they were largely confined to use as subwoofer amps for a long part of class D history. Reminder -- commercial class D amplifiers have been on the market since 1975.
I'm sure there have been very poor class D amps in their history, same as all the other classes. But where is the evidence that amps from the last 10 years that have low output impedance have a problem.
Some other points.
As Frank points out this is not class D.
There is no evidence this amp has frequency response issues.
SAM only works over sub-woofer frequencies.
 
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T-NYC

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I am afraid you are quite wrong.
Where on earth did you get this idea from?
I know their chief engineer quite well and I know exactly how it works.
You have picked up a mish mash of typical internet misunderstandings.
It is similar to current dumping but your explanation is in every other way incorrect.


Frank, as you are making the claim it is similar but different -- prove it! Explain convincingly how this is the case.
 

T-NYC

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I'm sure there have been very poor class D amps in their history, same as all the other classes. But where is the evidence that amps from the last 10 years that have low output impedance have a problem.
Some other points.
As Frank points out this is not class D.
There is no evidence this amp has frequency repose issues.
SAM only works over sub-woofer frequencies.

If you were to look around you would find enough, beginning with the large number of class D amps that are sold for subwoffer and non-hi-fi use. Since you believe SAM is something else, then what else is it other than a frequency response alteration?
 

T-NYC

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When your really good friends with Bruno you get to call him Pruno .

Yes, I did not wish to point this out to the Devialet enthusiast, who is already submerged trying to comprehend that in ADH, the D refers to Digital.
 
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