Absolute Sound's thoughts on Class D not ready for Prime Time?

warnerwh · « **on:** 9 Oct 2006, 03:59 am »

If anybody has read this months edition of Absolute Sound you know that the primary theme is Class D. In the end it appears that the general consensus is that Class D is not ready for prime time high end. At least that's what I read into it.

I'm just wondering what other people's thoughts were on these articles. I'm not interested in opinions of any class of amplification, just the impression received from reading these articles and reviews in the current Absolute Sound. Thanks

Bob Reynolds · « **Reply #1 on:** 12 Oct 2006, 04:04 pm »

I found the technical overview article by Robert Harley adequate. But I thought there were a couple of points he made that were not specific to class D amps. I think he missed an opportunity to compare to class A/B.

The designer roundtable discussion was the highlight of the issue. Each made very valid points and exposed enough of their personal philosophy to let consumers know what to expect from their products.

The reviews and the editor's roundtable, like the rest of the magazine, is a waste of paper for me. Unless the review is written by Robert E. Greene, I can not wade through it. The Audio Critic has spoiled me.

I also found the last page mini interview with Kevin Voecks of interest. Not as in depth as the one years ago in The Audio Critic, but still good enough to let people know what's going on at Revel.

Kevin Haskins · « **Reply #2 on:** 12 Oct 2006, 04:16 pm »

I'm going to have to pick up a copy. Was Bruno Putzeys one of the panel of designers?

Bob Reynolds · « **Reply #3 on:** 12 Oct 2006, 08:14 pm »

Quote from: Kevin Haskins on 12 Oct 2006, 04:16 pm

I'm going to have to pick up a copy. Was Bruno Putzeys one of the panel of designers?

Yes, he was and quite impressive from my perspective. Also, much younger than I expected. He seems to be a prime example of the engineering talent hidden away within corporations.

bummrush · « **Reply #4 on:** 12 Oct 2006, 08:16 pm »

Bruno was about the only one who brought any sense to the article,thank God,everything compared to mega,mega buck equip.How the hell do ya think the story is going to go,that article just seemed to different for some weird reason,kind of hard to pin down.Has anybody heard the Cary?

Kevin Haskins · « **Reply #5 on:** 12 Oct 2006, 09:15 pm »

Quote from: Bob Reynolds on 12 Oct 2006, 08:14 pm

Quote from: Kevin Haskins on 12 Oct 2006, 04:16 pm
I'm going to have to pick up a copy. Was Bruno Putzeys one of the panel of designers?

Yes, he was and quite impressive from my perspective. Also, much younger than I expected. He seems to be a prime example of the engineering talent hidden away within corporations.

I've been extremely pleased with him. He has helped me on a couple board designs and not only is he knowledgable, but he is a nice person to deal with. Both him and Jan-Peter are very responsive to my needs. Great people to do business with...

ctviggen · « **Reply #6 on:** 12 Oct 2006, 09:19 pm »

Supposedly, Bruno Putzeys is THE MAN when it comes to "class D" (which really is a misnomer). He even emailed me out of the blue when I was on the DIY forums, regarding an issue I had.

macrojack · « **Reply #7 on:** 12 Oct 2006, 11:54 pm »

The only reason to care what TAS thinks about anything is the impact it will have on sales or resale. Their reviews may as well be written by the manufacturers themselves.

Kevin Haskins · « **Reply #8 on:** 13 Oct 2006, 12:44 am »

Quote from: macrojack on 12 Oct 2006, 11:54 pm

The only reason to care what TAS thinks about anything is the impact it will have on sales or resale. Their reviews may as well be written by the manufacturers themselves.

Hmm... maybe I'll advertise in TAS. I didn't know you got to write your own review.

warnerwh · « **Reply #9 on:** 13 Oct 2006, 03:33 am »

Quote from: Kevin Haskins on 13 Oct 2006, 12:44 am

Quote from: macrojack on 12 Oct 2006, 11:54 pm
The only reason to care what TAS thinks about anything is the impact it will have on sales or resale. Their reviews may as well be written by the manufacturers themselves.

Hmm... maybe I'll advertise in TAS. I didn't know you got to write your own review.

It's about as close as it gets to writing your own review. I've lost almost all respect for professional reviewers and both Stereophile and the Absolute Sound.

If you want a review remember that they will be asking for a handout before the review happens. At least I know manufacturers claim they've been asked to buy advertising space before the review, I have no first hand knowledge. You may want to ask Frank. It seems like extortion to me.

Kevin Haskins · « **Reply #10 on:** 13 Oct 2006, 03:59 am »

Quote from: warnerwh on 13 Oct 2006, 03:33 am

Quote from: Kevin Haskins on 13 Oct 2006, 12:44 am
Quote from: macrojack on 12 Oct 2006, 11:54 pm
The only reason to care what TAS thinks about anything is the impact it will have on sales or resale. Their reviews may as well be written by the manufacturers themselves.

Hmm... maybe I'll advertise in TAS. I didn't know you got to write your own review.
It seems like extortion to me.

Me too... I understand the economics though so I try not to take it personally.

denjo · « **Reply #11 on:** 13 Oct 2006, 08:35 am »

When thermionic tubes ruled the audio arena and solid state amplifiers were introduced with its first offings in the early 1960s, there was great controversy and skepticism about the "new technology". Solid state amplifiers have been with us for about 40 years and it is interesting to note that today class A/B technology appears to be the most common and widely used means of audio amplification, with class A tube enthusiasts in the minority (though there appears to be a resurgence of interest). Then came class D technology. Again, the shroud of controversy and skepticism surrounding class D technology sounds like deja vu, and the debate of yore that seemed so heated between tubes and solid state!

Here is an excerpt from Stereophile's archives http://www.stereophile.com/historical/565may/ with John Atkinson's editorial note and J. Gordon Holt's article of 1965:

Stereophile Editor's Note: "Those of us who cut our engineering teeth on tubes still remember the advent of the solid-state amplifier with mixed feelings. Yes, they were lighter and cheaper per watt than the thermionic hulks we loved so much, but they broke all the time (thanks to the germanium transistor) and sounded like—well, let J. Gordon Holt tell us what they sounded like in an "As We See It" article from Vol.1 No.10, first published in May 1965. We also develop the theme with a JGH review of an early transistorized amp, as well as a selection of readers' letters from the early days of Stereophile. Enjoy."—John Atkinson

Do read the article from start to finish, as well as the link at the bottom of the page [Article Continues: KLH Model 16 amplifier]and the Readers' letters that followed. If we substituted the phrases "tube" and "solid state" (or its derivative) with "solid state" and "class D" (or its derivative), respectively, there is an uncanny similarity with the debate today with class D amplifiers in general, and TAS's lukewarm reception in particular.

I would like end with a quote from J Gordon Holt, made with reference to the tube v solid state debate, but which I think also is the reason why there is so much skepticism with class D technology:

"The point in question is not one of potential quality, but of quality that has been available to date in commercial designs."

Class D has great potential to excel, and some of the designs that are at the cutting edge of technology, specifically addressing and successfully eliminating such issues as RFI, are already in place. I foresee that class D technology will continue to progress, with more and more amplifiers (including some sacred cows) embracing the new technology. I would like to see three streams running parallel with each other, respecting each of the technologies, but offering the consumer greater choices, and with it the ultimate of musical enjoyment! It is great to be an audiophile consumer in these new times!

Dennis

bummrush · « **Reply #12 on:** 13 Oct 2006, 03:21 pm »

From what ive heard class d will do just fine,

warnerwh · « **Reply #13 on:** 14 Oct 2006, 05:33 am »

The most important part of this issue has been the message I received. This being that no two reviewers has the same opinion, same gear etc.

What this means is that after you read something one of these people have written it may or may not mean diddly to you. It's a coin toss. In other words: WHY Bother?

Aether Audio · « **Reply #14 on:** 14 Oct 2006, 02:58 pm »

Hi guys!

I haven't been around for a while - busy, busy, busy - but it's Saturday morning coffee time so I thought I'd chime in on this one.

I get a kick out of all this audio industry hyperbole. A handfull of so called "experts" pretending to forcast the future and appear to be "coaching" consumers with regards to what is acceptable technology for the market - Ha!

The fact is that Class D is here to stay - regardless of anybody's opinion (other than the folks plunking down the $$$ for it).

It's all based on one principle...consumers are always searching to get more product for less money. That alone is enough to guarantee class D's ultimate success.

Besides the above, even if you were to strip away the entire audio industry, Class D R&D would continue and the technology would continue to improve. Audio bandwidth amplifiers are used throughout industry for all kinds of uses. Servo-motors, linear actuators, instrumentation amplifiers and MRI machines are just a few that come to mind. I know what I'm talking about here. In my engineering days at Crown International (1989 - 1996) we were deep into Class D amps for the MRI industry. Clear back then we had developed a Class D tracking supply that drove a linear output stage that produced 40,000 watts of atom aligning power! Trust me...reduced size and cost along with increased energy efficiency and power levels are the driving forces for industrial and scientific uses and will continue to drive Class D development.

And all the parameters that are important to the audiophile are also important in industrial applications. Reduced distortion/greater linearity, lower noise and the elimination of RF emissions are just as important for industrial apps as they are for audio. Even if the audio market were to completely turn its back on Class D, all the other industries would continue to drive its refinement. At some point, some engineer/audiophile that used class D in his day job would get the bright idea to market it for audio use. Then we'd be right back were we are now, except the technology would be even more advanced than it is at the present time.

So I say...face the facts: Class D is here to stay and it's just going to get better. As a consumer you may want to hold out until it matures a little more - and there's no right or wrong in that regard. But if I were a Tube or S-S, Class A, B, A+B, SET, etc., manufacturer that was hell-bent on refusing to develop a Class D product...I'd be banking what profits I have now for early retirement!

Take care,
-Bob

Bob Reynolds · « **Reply #15 on:** 14 Oct 2006, 03:46 pm »

As Bob states above, there is little doubt that class D amps are here to stay. And he's right that the driving forces are size, efficiency and price. Tube and solid state linear amps are here to stay as well.

For me linear solid state designs have made electronics a non-issue. I look forward to advances in speakers, room acoustics and digital correction of both.

Bob Wilcox · « **Reply #16 on:** 15 Oct 2006, 12:19 am »

I think the analogies miss something. I remember the glory days of tubed Fisher consoles and the like. IMHO, solid state electronics still sounded pretty horrid at the point where most manufacturers cut over to solid state designs. CD players still sounded terrible when vinyl was replaced as the dominant media for music distribution. Whatever the gulf may be between Class D implementations and other design implemntations, I find it of far less magnitude.

Although Class D amps have been around in some form for many years (including car stereos), it is only in recent years that they have been offered by multiple companies as high end contenders. Many purchasers of Class D amps have abandoned comtemporary solid state and tube amp designs because they perceive sonic superiority in some areas - not just on the basis of the reduced size and increased efficiency possible.

IMHO, Class D is a viable alternative positioned for potential dominance and currently at a more evolved state of development as a deployable technology than when the solid state receivers and CDs that were rammed down consumer's throats by market forces. If I owned Krell, I would make sure I had multiple objections to Class D too. And I would be trying to come up with additional objections.

Bob

JoshK · « **Reply #17 on:** 15 Oct 2006, 12:50 am »

IMHO ABS's opinion on the matter is inconsequential, in fact I think ABS is inconsequential, but less so than Stereophile.

celebrat · « **Reply #18 on:** 15 Oct 2006, 02:08 pm »

I felt the discussion was mostly controlled by "Krell". "If it cant produce a clean sine wave it is not a viable or complete format" to paraphrase our buddy, Dan D. Of course his amps sound better than tube amps as well ...right?

And pricing is so reasonable

Would have been interesting to hear the panel's take on Red Wine Audio. I dont know about sine waves, but I do know my ears...not to mention value and my pocket book. Of course ABS, Krell, AR, Kharma are not particularly well served to discuss a remote controlled integrated amp under 2k that kicks the #$^& out much of what is out there. Just my 2 cents. Your milage may vary.

beachbum · « **Reply #19 on:** 15 Oct 2006, 02:48 pm »

i say amen celebrat, let your ears do the listening, no doubt people have there own agenda, and hi end is a big profit business, and its up to you to sort through the muck and put your system together with your ears telling your wallet to make the purchase, mike