Class D amplifiers. What's the future look like?


I have a number of amplifiers: Luxman C900U, Bryston 4BSST2, Audio Research VSI 60 Integrated, NAD C298 and some other less noteworthy units. As I swap them in and out of my main system, I've come to the conclusion my very modest NAD C298 is about all I really need. Granted if I had extremely hard to drive speakers, I might be better with the Bryston or Luxman, but driving my Harbeth 40.2 speakers, the NAD is just fine. 

I thought a while ago that class D would quickly overtake amplifier design type mainly due to profit margin which I think would be much greater than A/B and tube. I'm not saying the other design styles would go away, just that D would be the most common style. 

Clearly my prediction is not panning out, at least in the mid and high-end audio world and I'm wondering why? It seems companies such as Bryston, Luxman, McIntosh, Hegel and so many others are sticking by A/B. I'm no "golden ears" guy, but is the perceived sound issue(weather real or imaginary) still holding D back? Maybe my assumption of profit margin is not correct? Maybe the amplifier manufacturers are experimenting with D, but keeping tight lipped until release? Perhaps brand loyalists don't want change similar to what happened with "new coke". What else am I missing?

 

128x12861falcon

Great post from atmasphere answering the Quotes from decade ago...

it seems that class D and related design initiated a revolution , it is not an upgrade among other upgrade choices but another audio level not only for high end designer as him but for consumers  ...

😊

 

 

@agdproduction 

great quotes, all of them. I guess there have been members of the Flat Earth Society since time immemorial…. Luddites of the world unite!

@deep_333 I've seen that list of quotes before. They got debunked due to their age. 

A lot of those quotes you listed are from nearly 20 years ago. At that time I was of the same opinion as seen in them. One way you can date the quotes: look at Thorsten Loesch's comment about a 300KHz switching speed. No-one has made class D amps with that low a switching speed in a very long time 😁

So these comments can be discounted as simply out of date.

Your comment about GaNFETs seems a bit uninformed to me. Its not that GaNFETs are somehow 'the answer' so much as when they started turning up was also about the time that class D got a lot better figured out (and that was ten years ago...).

There's long been a tubes vs solid state debate on the internet, older that the internet itself. All technologies improve in time so one can safely conclude that sooner or later solid state would get good enough that tubes would simply be eclipsed. To tube aficionados like myself this also means that that new technology will eclipse solid state A and AB amplifiers as well.

I cannot speak for other manufacturers, only myself and that should be taken with a grain of salt since I am associated with a manufacturer. I've made no secret that I replaced my triode class A OTL amplifiers with a set of class D amps about two years ago and I don't hear any tradeoffs whatsoever. The class D amps are every bit as good and better in some ways then the OTLs. FWIW, the OTLs have been getting rave reviews and awards in the high end press since sometime in the 1990s.

As a result I'm of the opinion that class D is something to be reckoned with and isn't at all as you described; it dominates what we in the high end audio world call 'mid fi'- stuff you get at Best Buy and the like. Its been making inroads into high end the last 20 years and at this point, seems evolved enough that any manufacturer of amplifiers will be going out on a limb if they don't get class D figured out. Its that simple.

@atmasphere , It really comes down to one's 'point of reference', i.e. what type of gear a dude's spoilt by or not, what type of gear he grew up with (what type of gear created his taste pallet to begin with, etc...).

I grew up listening to my old man's class A vintage Pioneers and so on...That type of sound sticks with you, y'know? I spent years with most of Nelson Pass's stuff, cycled through some of Gryphon's stuff, etc, etc and this is my current list (spread out among different rigs)...

Luxman C900u+M900u, Yamaha C5000+M5000, Technics SU-R1000, Schiit Tyr, Zhongshen Class A, i.e. this is my point of reference at the moment. I am done buying sht for now.

But, for years, or atleast since 2000, i've been probing Class D every few years. The primary goal there was to not have space heater amps running in the room ---> Frequent HVAC activity ---> increased HVAC induced noise floor ---> loss of fidelity. I tried, but, every freaking time, i was let down by them. The Technics was the most i was able to deviate from Class A/AB, but, even that amp feels like a letdown some days. 

I wish my ears were more forgiving. I think I could make some Class D work for my ears with tube line stages and dacs, but, i really don't want to deal with the confoundedness/pestilence/mainteance crap with tubes anymore...

Some pieces can spoil a dude and maybe it makes one's likes/dislikes appear a bit stronger (more pronounced in articulation perhaps). When i am a guy on the internet, i am joking about stuff. It makes me live rent free in @soix 's head somedays, for instance 😁. But, i've walked into houses of dudes in my area with all kinds of gear at all kinds of price points and i don't say anything to hurt their feelings. I have a few drinks and i'm rocking with any kind of gear, i.e., I am a doll in real life. 😁

I am sure your stuff would be great for a lot of guys.