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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Woodburger and Bbro have said it. Synergy is where it is. I have found naked speaker cables make night and day differences. Same goes for non-oversampling. The preamp choice is paramount as well.

As class D amps continue their spread, we will see cable and preamp builders bringing out more great class D friendly gear.
"NuForce, when does not need to drive difficult load which it can't, doing admirable job too."

My Nuforce's have zero problems driving my Aerial 10T's and they are certainly not what I would consider an "easy" load.
I was not a fan of class-D amps untill I heard the H20 Signature monoblocks. They changed my mind.
I agree that Class D amps have a lot of potential. We have only scratched the surface of this new technology. It may not be quite there sonically yet but it is getting closer, and according to some as stated above, it is as good or better than conventional amps. There is a lot to be gained in terms of size, efficiency, cost, etc. And don't forget that some amps with conventional output stages have been designed with switch-mode power supplies.
I am late to this party,but want to give a simple opinion.
Firstly, virtually all new technology gets "knocked" when first introduced.Nobody wants to give up their present stuff.I don't think any owners of Class D designs should get nervous,from some criticism,especially if it sounds good to you.You cannot have too bad hearing,or you would not be in this hobby!!
Secondly,the Abs Sound forum is yesterday's news,as it took place a while ago,and technology has improved since then.I do remember Jeff Rowland stating he would use whatever "modular" technology he felt was advanced enough,and good sounding enough to put in his stuff.He seemed open minded about the newer technology,and wanted to embrace it,while it appeared(to me) that Dan D'agostino was intentionally contradicting Jeff's input.Look what has happened to Krell,these days....Just a thought.
I don't own a "D" class amp,but did have Jeff put in two of the industry's latest Switch Mode modules in the power supply "second" chassis of my "two" chassis 8T amp.I previously had an older S.M. module which replaced and outperformed the battery held within the second chassis.I didn't think it could,but it most certainly was quieter and far more dynamic.
I was extremely happy with the battery,but the new S.M. "original" update was considerably better,period.Believe it or not!!NOW the dual module S.M. power modules that have gone in recently, absolutely outclass both the battery,and first (superb sounding) S.M.(switch mode)power supply.Who knew?
I was sceptical at first but the performance is rediculously good!....The amp runs COOL too!!To me "that" is a "cool" thing....My previous Krell mono blocks,which sounded just fine(driving my Avalons)required a dress code.Which was to wear nothing but a Speedo,even in the dead of winter,due to the rediculous heat output.....Sometimes one actually likes to be comfortable when listening to music.
My tube amp days were fun,but I would always use my tennis sweatbands,during long listening sessions.I am serious.Not really!!-:)You know what I mean.
As to the actual class D stuff..in all honesty,and of course only my opinion.....I have heard the Nuforce amps,and the Belcanto amps,as well.I was "extremeley" impressed with their sound quality.I,also,was sitting in comfort during the listening sessions.Of course I did not bring my son,the doctor's(had to slip that in-:)stethescope with me,to see if I could make out any wrong doings in the music.Whch sounded great,btw.
The future looks bright for these designs,and I could care less what a reviewer thinks.It is my own ears,and comfort that matter to me.
Best regards.