Class-D amps - a different re view


Martin Colloms, the editor of HiFi Critic (ad-free mag from the UK) have recently published the review of several different Class-D amps, together with an in depth technical analysys and measurments.

His conclusions were not favourable, to say at least:

"I regret that not a single model merits unqualified recommendation. Price is not the issue; the poor listening tests speak for themselves. (...)
At present we have to take the prudent view that good sound might be possible from switching amps, but we haven't heard it yet."

BelCanto REF1000 (ICEpower) - score 10.5 pooints
"The ICE power module used has a dependable reputation, and the design is well built and finished as a whole. While I would not suggest that you shouldn't try this amp, on sound quality grounds alone I cannot recommend it for audiophile use."

Channel Islands D100 (UcD) - score 13 pooints
"While I have reservations about a number of aspects of sound quality, and advise personal audition, given the solid lab results (...) the overall performance and the moderate price, these CA Audio monos do make it to the 'worth considering' cathegory."

NuForce 8.5V2 (proprietary technology) - score 9 pooints
"Yes, the price is good for the power output. Yes it's pretty, light, small and runs cool. However, the sound quality simply does not justify recommendation." (on top of that the NuForce amp measured very poorly - Elb)

Pro-Ject Amp Box (Flying Mole) - score 5 points
"I'm sorry to say that Project (...) was a real disappointment in the listening tests, and can't be recommended."

Just as a point of reference, recently reviewed Krell 700CX scored 100 points, CJ Premier 350 - 110 points and ARC Ref 110 - 135 points.

At least someone have had the balls to say it. This is why HiFi Critic is THE mag to subscribe.
128x128elberoth2
Mid-Fi huh. . . Oh Dear. . . I really did not realize the horrible implication of those scores! And I have been all along singin' the virtues of mere mid-fi trailer-trash electronics. . . how could I? What are my neighbors going to say if they only find out what questionable company I have been keepin'?! . . . I's so sorry I's so sorry. . . I really didn't know nothin' none of it!
Coffeey: "Sure they can sound good,but why oh why did they all get such a terrible low score?Not even in the 40's ,50's,what 8,10.13?Mid fi at best"

I think "4" might be better. Then the Accuphase A-50V should have a "3" and the Mark Levinson 333 a "2" :)

Chris
I will preface my remark by saying I have not listened to any of Class D amps except at a couple of the Audio shows so I won't attempt to argue or debate the issues of sonics but to follow up on Ralph's (Atmasphere) points; I don't think Ralph thinks/thought that we (most audiophiles) would in fact have our amps, pre, DAC's etc for 10+ years, although we certainly could if we got off this merry-go-round, Ralph knows the Audiophile weaknesses. The point as I see it is, tube amps will have value after that 10-20+ years where the "D" amp will be worth 000000. No one will be able to service the "D" amp if one of the chips or digital circuits should fail. At that point the amp is worthless. Case in point, I have several 50-60's Fisher, Scott, and Marantz pieces that are worth more today than the day they were sold new and in the Marantz case many, many times its original value. If I can't fix these pieces most qualified techs can get them back up and running.

Ralph if I have miss-interpreted your point please correct me............Bob
In an attempt to refocus the discussion, I'd like to point the gang to the recent blog followup by Martin Colloms:
http://hificritic.com/Scene/news.aspx
In his post Martin lists 17 different measurable flaws he seems to have uncovered in the reviewed samples. I have heard only the current version of the Channel Island amps and the older Evo2 series of Bel Canto, while I have not heard the latest Bel Canto series nor I have any experience at all of the other two brands. I admit I have detected some slight artifacts in the Evo 2 and perhaps more so in the Channel Island which may be congruent with his observations. The problem in his analysis is rather that -- once again -- he jumps to generalizing conclusions by extending a priori these flaws to all and every switching amplifier implementations on the market today. I have no qualms with his analysis. . . the problem is all in the logic of his induction step.
While I have not A/B'd the "new" hi-tech "class-d" designs with any other amps,this discussion is becoming a bit silly.
The audiophile attitudes toward one's own particular set of "what one likes" should not overcome the "obvious",which is 1...Progress(like I stated earlier,this will not even be a discussion in the not distant future).#2...the fact that there is a growing contingent of music lovers who hear enough of Class-d's virtues to invest in them(they cannot be all deaf).3#...the arguement of the tube afficionados(of which I am one,btw)remains consistent,regardless of technological or performance improvements.#4...With the HUGE advantage of LOW heat(actually almost none),low cost,and small size one has to be really foolish to believe that a "matured" Class-d design(sounding great,by any standard)is far away.
As to obsolescence.....PLEEEEEASE!!!By the time a really good Class-d design is ready to get "dumped" by a particular owner(unless one is on the non stop merry-go round)what do you think the price of GOOD NOS TUBES will cost??Sort of makes up for the costs of new amps,almost!Based on the going trends!
BTW,I have no interest in buying anything,in the near future,but like to think I am open minded,and still have some pride in my current hearing!
My Tube loving friends have been almost militant about any other design formats.To my way of thinking it is their loss.