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
In answer to Jdillard.

Yes most class D switching amps do use the B&O with the expeption of Spectron, which use their own proprietary module plus a lot of very high speed sampling/feedback plus a very large transformer. I have listened to the B&O based units and the Spectron (Musician III) and the difference is very significant. And I agree with Jw94055 that a tube preamp is definitely advised.
My Nuforce 9SE V2's are the best I have ever heard. They blow me away. More reviewers agree then disagree. Just listen to then folks. I hit an endpoint in amps. Different sounding amps yes, better sounding amps perhaps, but these are really very special. The soundstage is simply as good as you will ever want or need. There are no side walls, back walls, or speakers. These are very clean and clear and never run out of steam in my system. Dali MS'5's and Modwright CD player. Move over vinyl. Finally.
Agree. The Gilmore Raptors have substantial linear supplies.

This is one feature that allows them to produce very little RF noise of their own. When I added them to my system, I was able to track down and ameliorate external RF noise sources in my house. It turns out that every major appliance these days has a computer and a switching power supply inside, and most of these run continuously even if the appliance is idle.

For example, our dishwasher and clothes dryer are significant RF noise sources just sitting there. Appliances such as microwave ovens and digital video recorders are obvious, but it is amazing how much the audio system improves by just switching off the power to the dryer at the breaker panel.
This conversation will be moot,in the not to distant future.
Also,with all due respect,why would a Hi Fi reviewer have any better ability to tell whether a product(of any type)is good,as compared to any other "music lover"?
In the sports world,or as a musician,one spends a great deal of time making themselves better than the average person,at their craft.I'd love to know how I can "pump up" my hearing,and improve it more-so than they already are.
Just a thought.
"Also,with all due respect,why would a Hi Fi reviewer have any better ability to tell whether a product(of any type)is good,as compared to any other "music lover"?"

IMO, a reviewer's value stems from his access and exposure to a variety of associated and competing products. That's why I'm always amazed when I read a review, and the reviewer admits he hasn't fully exploited this advantage.