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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

Showing 3 responses by dob

dob
577 posts
 
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... ;--)
dob
577 posts
 
Elberoth - You are exactly right. The best sounding class D amplifiers - Spectron Musician III Signature and Kharma using linear traditional non-switching power supplies, and I been told by Spectron people - only due to the sound.

RF contamination indeed is a major source for sound degradation in class D - again Spectron people told me that when they re-designed RF filtering circuitry for Signature the sonic results were very impressive.
All The Best,
Rafael
dob
577 posts
 
"pls look at the Nuforce site under the award and review menu....the quantity of enthusiastic reviews by TAS, 6moon, Stereotimes etc is embarassing!!!!"

Drooling is embarassing indeed. If you look again into TAS review - it is compilation of three different reviewers. two gave excellent review and one terrible.

Why? Is this one professional reviewer is deaf? No, read again TAS it gave NuForce Editor Choice Award but with the caveat - ineractions with cables (and obvuously speakers).

I know this amp cannot drive electrastatic Martin-Logan speakers (not poorly drive but not at all - coming the the region of difficult impedance and shut itself (v1 for the record).

Without going into engineering as to why let me simply state that despite multiple positive resonse and even drooling ==> BUYER-BEWARE !!!! Good amplifier but not for every speaker!
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