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
Points well taken, Bob. As an example that supports your observations, I just installed Sonicap Platinum bypass caps, and like what they have done. My speaker cables are short. I have found SC and IC insulation pollutes the signal significantly. I have yet to do binding posts or isolation. Any suggestions?
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
Phaelon,I should have said.."any music lover with a goodly amount of experience in this hobby".I have been at it 39 yrs,and most of my friends have been at it at least as long.
None of us subscribe to any particular system/product topology.If it sounds goo,it is good.
BTW,living in the tri state N.Y. area I have been fortunate to be able to actually hear quite a few personal set-ups,owned by reviewers I am sure you have read.To my taste(only an opinion)some sounded quite good,and some were absolutely dreadful sounding.
Btw,I DO understand your valid point,and am in no way trying to disrespect your posting.
Best regards.
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