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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Martin Colloms is a highly regarded & respected reviewer. I agree with his asessment that Class D amps don't quite measure up to audiophile use but they are fun toys. I've tried a few of the above mentioned/reviewed Class D amps and have sold them and have gone back to conventional designs.
Our collective point is, Phd, you can't just try a class D amp, It takes a commitment to find out what brings out any class D amp's best. Some folks are lucky and have equipment that works well with their new amps. Others have hose cables, high impedance preamps, bad performing digital, or unshielded power cables, any of which can foul the sound.

I want to get a copy of Mr. Collin's article. I don't know about others, but my system would cream anything he has that uses his favorite conventional amp.
Muralman1, that is a good point that experimentation & patience are important to get the best results from Class D amps. I know that some class D amps are transparent as hell but what I didn't like is that some designs lacked body, that weighty full sound you get from conventional amps, but all class D amps are not created equal. Also it has been mentioned before that class D amps should not be compared to analog and should soley be judged on their merits as a somewhat new technology.
It is important to realise that switching amps use one of a variety of different designs, there isn't a ubiquitous Class D design just as there isn't for SS or tubes. The issue about loads applies to some of them, not to others. I have tried Ice modules, UCD, and Nuforce and while they all have the benefit of not suffering the characteristic sounds of SS or tubes, they nevertheless had definite different characters. Studying their designs it becomes obvious that their designers each chose a different set of trade-offs, and by the way each has a readily identifiable design weakness of some type. The present is bright already for these designs and the future looks even better as it seems to me that the application of a bit of art to the basic idea will push them well past SS and tube amps over the next decade.
"I want to get a copy of Mr. Collin's article. I don't know about others, but my system would cream anything he has that uses his favorite conventional amp."

<---- Good lord your a loonie!