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
class d works great for bass amplifiers Ive tried many some costly as all heck.Not my cup of tea. Maybe in a few years time class d will sound better for audiophile use.Till then I use ice moduals as bass only amps.
PHD,I understand your point,and intent.I have no problems with this,and wish you the best.Please understand I am not arguing about specific match-ups,in a controlled environment,which a reviewer(and some lucky hobbyists,with extra dough)is privvy to.
I must add though,I have made the aquaintance of quite a few reviewers over the years.A few are still friends of mine.There is definitely a contingent of "some",sadly,who are hobbyists,and getting a break on equipment is what got them into this,in the first place.I do not meander too closely to these "guys".
Yes,some get paid(according to my sources, "on time" payment can be like pulling teeth,at times),but I don't believe it makes for the lions share of their income.Kudos to them,and I could not go through the constant swapping in/out of stuff.They are certainly patient,and dogged in persistence.
As to the better ability to make a judgement,as compared to the average audiophile....based on your "very good" arguement,I'd agree with you(in those specific circumstances),but I have heard more than a couple of set-ups(at reviewers' homes)that were not in the same performance class,as some of my "average" audio pals.Actually,they are quite experienced.
I mean NO disrespect!My particular tastes are unique to me(btw,I have been at this almost four decades)and I have learned that I want a particular "voicing" of the reproduction of music,in my given room,to sound a certain way.My way,for me.
Many of my audio group(some retired scribes)are adamant about hearing things,as they want it to "impress" their own tastes.I cannot tell you how often there is a disagreement,amongst them,with the "latest" rave,or even good review.It often totally contradicts a given reviewer.
Of course,I would not want to be without the benefits of reading good "responsible" reviews,and DO believe there are quite a few fine reviewers(my favorite being Srajan E. of "Six Moons"... He seemingly a very down to earth and responsible writer and I hope I spelled his name correctly).
Experience tells me to take a good review with a grain of salt,and auditioning something in person IS the only way to go.
Even you have seen,too many times,specific high profile reviewers(I won't mention who)go crazy over a given component(and yes,plenty of folks jump on these products,just from reading the review)and make mention of significant shortcomings suddenly noticed some months later.For whatever reasons.Money well spent,by the highly influenced purchasers?I was at an importer's home,after J.V. wrote the, well deserved, good review,of the Kharma 3.2's.He sold 19 pairs,that week,over the "phone".
So,with due respect(and believe me,I consider you someone to admire)I can't see anyone with a good set of ears,not using their own intuitive instincts, to make a buying decision,first and foremost,and being confident in their own decisions.
The reviewer's job,to me,is to point us in a direction he/she feels is the right path,but sometimes it won't jive with where we want to go.
warmest regards.
Sirspeedy, it is excellent that we have all agreed that a reviewers conclusions are a matter of opinion but can point one in a certain direction resulting in either a positive or negative experience. Although most of us read reviews from time to time some people pay little attention to them. An example would be of a local hifi dealer that has been in business since the forties. I have gone in there enthusiasticly with a glowing review in hand over a certain product. His response was I wouldn't give you two cents for any review and recommended trying the product first hand to see for myself.
"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."

Yes, that is prudent a view indeed. It looks to me like the author seems to have sampled a narrow mixture of usual suspects built to a narrow pricepoint, and not necessarily the latest versions of at least one of them. Obvious holes in the samples are the Spectron Musician 3 Signiture sitting towards the top of the price sampling range, definitely worth a listen. . . or 2, or 3 times )(see Neil Gader's review update in TAS 176); JRDG has a lineup of class D models ranging from $4K to $30K with a proportionally wide spectrum of musical performance characteristics among which the 312 remains my current favorite amp of any class; Genesis has models ranging from under $5K to over $25K; Kharma has 2 models if I recall, one set of monoblocks for under $10K and the other reference level set costing perhaps $40K or so; Mark Levinson is preparing a set of reference level monoblocks in the $40K range. . . . I bet I haven't even scratched the proverbial surface. I venture to suggest that the author may want to consider broadening his reviewing sample starting today. . . he may find some results of current implementations delightfully surprising. . . As for tomorrow, it is in the future and as such is not worth talking about.

Guido D. C.
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.