2. amps-preamps
  3. 1192052948

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
muralman1
1,527 posts
 
Sajran has quality sources, keen knowledge of what actually works in given systems, and an open mind. Read his review of Henry's H20 amps done a couple years ago.

I have monos of his that have a B&O improved ICE module, and much better bypass caps. The sound just got better.

Class D amps, the great ones, must be fed impeccable signal. Any source, wire, and pre-amp negatives will be exposed, much to the listener's discomfort.
sirspeedy
738 posts
 
PHD,I must add that you ae definitely a gentleman!
BEST.
traver02's avatar
traver02
5 posts
 
Absolutely agree!!!!
Nuforce Ref 8.5 was quite an old piece of hardware, even the difference between Ref 9 and Ref 9V2 is huge.
So the comparison between D-class models should be done with the current amps version that is Ref9V2.

I recently added the Nuforce Pre P9 to the chain...

Never ever heard something like that!!!!!
but you do not have to believe me!
Listen to a Nuforce chain to a dealer near you!!!!

pls look at the Nuforce site under the award and review menu....the quantity of enthusiastic reviews by TAS, 6moon, Stereotimes etc is embarassing!!!!
but listen before judging!
dob
577 posts
 
"pls look at the Nuforce site under the award and review menu....the quantity of enthusiastic reviews by TAS, 6moon, Stereotimes etc is embarassing!!!!"

Drooling is embarassing indeed. If you look again into TAS review - it is compilation of three different reviewers. two gave excellent review and one terrible.

Why? Is this one professional reviewer is deaf? No, read again TAS it gave NuForce Editor Choice Award but with the caveat - ineractions with cables (and obvuously speakers).

I know this amp cannot drive electrastatic Martin-Logan speakers (not poorly drive but not at all - coming the the region of difficult impedance and shut itself (v1 for the record).

Without going into engineering as to why let me simply state that despite multiple positive resonse and even drooling ==> BUYER-BEWARE !!!! Good amplifier but not for every speaker!
warrensomebody
8 posts
 
I wanted to believe... but all I can say is my take on class D amps is that their performance must be highly dependent on the system they're plugged into. I had read all the glowing reviews of the Bel Canto Ref 1000s, and sprung for a pair and was sorely disappointed. I tried them on my nearfield towers and they sounded weak and thin -- all treble and no midrange at all. Then I tried them on the subs, and it was the same story -- extremely weak bass response. I A-B'd them with several other amps I had on hand, and they were dramatically worse than all of them (a Classe 10, Proceed HPA-2, and a 300B SET).

A friend with an electronics background offered a theory on why they didn't work for me -- I'm not sure whether it's true or not, but I'll offer it here to see if you guys have any thoughts on it... He said that the performance of switching amps like the Ref 1000s are highly dependent on their ability to draw current from the wall. If the power lines can't deliver the current needed when the amps demand it, they completely fail to deliver the signal. I don't know if that was the case here at my place, but they definitely didn't work for me.

The Bel Cantos taught me a valuable lesson -- you can't just go by reviews. For the forseeable future, I'm sticking with amps with big capacitors.
More to discover