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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Showing 5 responses by phd

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.
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.
Sirspeedy, I would like to offer some thoughts on why a HiFi reviewer may have the ability to be more accurate on his conclusions on any given product over that of the average audiophile.

It isn't that the reviewer's hearing is more acute than the average person. Note, they also bring to the table their own personal preferences & expectations on what sounds good but none the less reviewing products is what their paid to do & thats what they do all day. Also they have at their disposal several other pieces to try with the product that is under review. Not to mention a large stash of power cords and interconnects to experiment with that sometimes cost more than the piece itself. I would like to think their opinions are unbiased & not influenced by the magazine they are writing for nor the company that is submitting the product for review. Over a period of time of reviewing different products & if most readers agree with their conclusions they will build a good reputation for accuracy.

Class D amps have alot of potential and although Martin Colloms has basically dismissed them as less than audiophile grade, it really comes down to a matter of opinion as there are other reputable reviewers & users that have reached different conclusions. In fact some models have attained a Stereophile Class A recommendation. For myself I will always keep an open mind & continue to read other peoples opinions & recommendations with great interest although I have expressed my preference for analog amps, that could change in the near future.

Stehno, that is what I hoped to convey in my post which is why you and I are actually in full agreement.
Sirspeedy, it is excellent that we have all agreed that a reviewers conclusions are a matter of opinion but can point one in a certain direction resulting in either a positive or negative experience. Although most of us read reviews from time to time some people pay little attention to them. An example would be of a local hifi dealer that has been in business since the forties. I have gone in there enthusiasticly with a glowing review in hand over a certain product. His response was I wouldn't give you two cents for any review and recommended trying the product first hand to see for myself.