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
I haven't read the review or the system he used to evaluate the amps. But I would guess a reviewer would use as revealing as possible setup. In my limited experience, I'm not so sure that would be the best for evaluating Class D amps. If anything, they are highly revealing themselves.
I have the CI D200's driving Vandersteen 3Sigs. The Vandy's are on the dark/warm side. The CI very much brings out the best of these speakers. It's as if a thick blanket was removed when I went from my McCormack RevA Gold to these. At first, it was distracting to hear that much more resolution and imaging. The Vandy's still retained the subtle warmth, but added the accuracy.
Point being what's been said many times.. system matching. I use a tube preamp (Modwright SWLP) like many others. I wouldn't pair them with SS or mini monitors myself. I thoroughly enjoy these amps.
Muralman1

Check out the Cardas site. Just about all of binding posts will fit the cut-outs on the H20. Avoid nickel in favor of pure copper or better such as the CCGR (short) binding posts. For RCAs, Cardas GRFA RCA chassis mount jacks are better than stock and not too expensive. A very hot soldering iron is required to replace the binding posts and the leads on the modules need to be unplugged to avoid heat damage.

For isolation, consider a pneumatic platform or FIM style bearing platform with ceramic bearings.

http://www.kosmic.us/resonance-fim.html

Bob
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.

Phd said,

"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."

There's a lot of assumptions there.

-IMO