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

Showing 10 responses by muralman1

ARC 110? You mean the ones I heard triamped on panel speakers run active? Oh well, to each his own.
Audiofeil and Elberoth2, The class D amps I have surpassed solid state amps costing 3 times as much by a wide margin in my system.

Not only that, these class D amps have uncovered a nest of attending components as the snakes they are.

That is because they have so little personality of their own, and as Dazzdax pointed out they are wicked fast. Minute details get through, both signal, and distortion.

You just don't know the beauty of class D if you match them with tried and true conventional gear.

Mrtennis. It is no secret why dug in audio companies detest class D. On my own system, Scintillas powered by advanced H2O monos, any listener can easily detect the pollution pressed onto the music by gaudy cables, flu flu preamps, and digitally smeared CDPs.

Some people think I am being sarcastic only have to spend awhile at my home to know I mean every word.

When retailers get four grand for speaker cable hoses, they are none too quick to warm up to the new class D amps that will expose their noisy dielectrics.

Class D amps have imposed rule changes. Wires must be clean. Analog signals must be left untampered by digital slight of hand like up or over sampling. Affordable preamps must improve.

If you ever took part in the passive vs. active preamp wars here and there, class D amps are the passive preamp champion's friend. Most active preamps do mess up the sound.

Ones that don't are expensive.
Not entirely, Tvad. There are cheap solid state amps, and tube amps too. They don't sound so good. The class D amps I have are not cheap. They are expensive to produce.
Tvad, you are correct. There is no getting around class D upsetting the audio business cart. ICE modules are everything you say. They are light, inexpensive, powerful, and ready for use in mass market items.

By creating a module, the 500A, that does not fit the above attributes except cost, B&O has thrown down the gauntlet challenging the small, but crowded, hi-end audio.
Elberoth2 - the H2O is made in America. That should tell you a lot. I have monos. The aluminum plates are made and finished in the USA. There are some 30 or more power caps.

Branimir, class D is not going to suit everyone. Besides, they are damn hard to coax great sounds from. There is no class D tradition to rely upon.

Some intrepid DIYer wrote a long piece on how to improve the H2O last year. That got me on the tweak binge, and found a great bypass cap choice.

I have already written on the importance of correct wiring, and my thoughts on CDPs.

Preamps have to be compatible with abysmally low impedences of ICE. The Fire preamp is tops in that category.

There you go guys, what makes those amps so expensive? The monos I bought cost me $5k.

Henry's amps are superb when matched with appropriate gear. Kharma's amps need the same care in matching.
I just posted. I don't go to the circles much. They aren't into mavericks there. Not that they are here either! :)