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.
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I recently heard one of the writer's favorite two conventional amps powering some Apogee Divas. I can't wait to get to the same place so I can wake up that tired sound with my class D amps.
As I said in my initial post - those are just his conclusions. The original review is 14 pages long - full of technical analysys, measurements and his impressions. The amps were very well run in (500h), he tried varoius power cords, varoius inputs, varoius cables, supports and associated equipment. It really is one of the most complete reviews I have read in a long time.

If anyone is interested how he came to those conclusions, I suggest you get the copy of the mag. Sorry, I cannot reprint more of his writing (I prolly already have broken some copyrights), especially that it comes from the current issue.

The mag is expensive (it has to be since it is ad-free), but it is worth every penny IMO.

BTW - I have nothing against Class-D. I have owned BelCanto eVo 4 mk II (Tripath based) and also evaluated for an extended period of time the ICEpower design in my system.

The original title for this post was "Class-D amps - a different (re)view" but somehow the brackets were removed by AudiogoN software. It changes the meaning a bit.
Martin Colloms is absolutely right - he did extensive listening and extensive measurements. Note that with exception of Spectron no other class D manufacturer disclose its full specs - and it should tell a lot!!!!

Entire panel of TAS reviewers come to the same conclusions in Nov 2006 issue 166 of TAS

Its is obvious that all owners of class D amplifiers would reject his/their conclusion because to accept it is to acknowledge that they did "poor" choice.

None less, people who auditioned Kharma monoblocks ($29k/pr) are very happy with their performance.

Spectron Musician III (one of the amps reviewed in TAS issue 166) received, this month, TAS Editor Choice Award without a single caveat.

As far as I know, three rave reviews (one in TAS) are coming to describe its Signature Edition.

There are superb designers in this world who produce...superb products.

NuForce, when does not need to drive difficult load which it can't, doing admirable job too.

I heard that Jeff Rowland $14k class D amp is also excellent.

So, its not all lost... ;--)
I wonder what Mr. Colloms will say about the Halcro next. I have a chance to audition the entry level Hacro Mc20/ Rogue 99 pre-amp/ Esoteric CDP with my LFT ET8b at the local hi-end dealer and I cannot believe what I am hearing. Ten years of loving for Martin Logan and Krell has been replaced by what I hear. I ended up with a pair of ET8b. The Halcro is next on the list.