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

@atmasphere @lalitk Just to be clear, I found the review informative and loved how he compared the new amps to the M-60 and found the GaN amp to lack nothing compared to an excellent OTL amp (just as Ralph has maintained all along). That part meant a lot and spoke volumes to me. What would’ve made it much more meaningful and interesting would be comparisons to another GaN amp — hell any GaN amp — that would’ve made for a much more effective, informative, and useful review IMHO. But that’s too much to ask from rags like HiFi+ and TAS who’d rather not do all that extra work and expose themselves to any potential accountability — heaven forbid!!!  I’m sure someone soon will write a truly rigorous review that I think a product at the level of Ralph’s GaN amp demands, and I very much look forward to reading that.

Where is his very precise review of these new mono blocks against all the LATEST class D or otherwise,,,,,done directly in his listening room, RIGHT NOW. NOT there....not there at all. How does the Atmas-sphere compare to a Benchmark amp, to a VTV high powered Purifi or Orhard with all my mods, or to the AGD amps or to Pass amps or to super tube amps in that price range, etc.? How are we to know anything about how it really is and compares with anything already available? All reviews need to be against a known reference in the same system at the same time or it is totally meaningless. The reviewer does not even mention any other amps nor the amps that he currently owns. This review is typical of reviews these days.....completely meaningless.

Agreed. HiFi+ and TAS reviews (among others) are utter garbage because they almost never compare the review sample directly to any competitive product and often don’t even disclose the relevant component in their reference system. As such, their reviews are basically useless and IMHO serve as nothing more than a product advertisement. My theory on this is twofold:

1) Not comparing a review sample directly to a competitive product almost completely absolves the reviewer of any accountability or being pinned down on any assertions he/she makes — they just wax poetic about whatever they “think” or “feel” at the time.  The mags that don’t do comparisons parrot the same line that “it’s unlikely anyone has that specific comparison piece in their system.” Hogwash!!! The fact is humans are very good at relative comparisons and much worse at judging individual things in a vacuum. Relative comparisons are almost always the most important and useful part of any thorough review.

2) It allows the reviewer, and thus the magazine, to spit out “reviews” at a much faster rate as making actual equipment comparisons significantly increases the time to write a review.

When I wrote reviews for Soundstage! a product comparison section was mandatory, and if a reviewer didn’t have or couldn’t get a comparable piece to do a relevant comparison to the product under review they didn’t get to do the review. Period. That, IMO, is the right and only way to do a thorough and meaningful review. Sorry for the sidetrack, but I thought @ricevs hit on a very salient point that warranted some emphasis.

@atmasphere , From what i’ve experienced thus far, the type of stuff you do could work for guys who mostly roll with midfi (they may think it’s hifi) or don’t have a high enough "point of reference". But, that shouldn’t worry you. You could still make enough money selling to those guys. IMO, what you won’t be able to do is convince guys who roll with any higher level of gear that your stuff should be sufficient for them as well.

Wow. Just…wow. The arrogance of this condescending statement directed toward one of the most respected amp designers in the industry without ever even having heard the amp is…wow. Speechless.

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.

Steeeerike one!

Your comment about GaNFETs seems a bit uninformed to me.

Steeeerike two!

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

Steeeerike three! Yerrrr OUT!!!

GAN is the 1 eared clown who has suddenly become the king of special olympics deaf clowns (Class lousy D). For anyone with 2 ears/normal hearing, King GAN is still very much a 1 eared clown.

Dogma run amok.  Anyone who values and respects the opinion, experience, and knowledge of @deep_333 over @atmasphere please raise their hand.  Joke.

I’d hope that 10 to 25 years from now, audiophiles will have access to great sound using these continually improved Class-D amps. That is after all why we all got into this, regardless of what technology we use to get there. Figure Class A, Class AB solid state, and SET or push-pull tube amps will be around for a long time, just because there will be some who will want them.

@moonwatcher Yup. My sentiments exactly. BTW I recently spent $$$ doing full upgrades of my McCormack amp (Class A/B) but came very close to going with a GaN amp. Came down to that I really liked the sound of my amp and the prospect of significantly improving upon that with SMcAudio upgrades just seemed like a low-risk option sound wise while switching to a different amp/technology might just end up being trade offs instead of a total upgrade. The devil you know…plus the upgrade was considerably cheaper than the GaN amps I was considering, so there’s that. It’s a journey fer sure.

Why is there this "push" to Class-D in the first place? What do you gain? In what way would they ever be sonically better than a good Class A or AB amp?

@moonwatcher Because it keeps getting better and better especially with the latest GaN and Purify amps that are being compared very favorably to top solid state and even tube amps.  When Ralph at Atmasphere not only designs a GaN amp but chooses to use it in his own system over his very highly-regarded OTL tube amps and that avoids all the expense and heat of tubes in a much lighter and more compact design it’s hard to deny the technology’s merit and future potential.  Plus, at least in the case of the Atmasphere and AGD amps, they’re upgradeable as the technology continues to improve.  The times they are a changin’ and ignore it at your own risk. 

If he really prefers his class D amps to tube amps then he fools himself. In any case, he is on this forum for business purposes, whatever he says - remember that

I think this post is off base. Ralph can use any amp he wants in his system but chooses to use his GaN amp — not really sure why he’d be fooling himself. And unlike some others here he never tries to “sell” his stuff here and mainly just provides very knowledgeable and helpful info to folks on the site and most of the time on topics that have nothing to do with his products. Not sure where all this cynicism is coming from.

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

I think not.  Sounds like you’re missing the newer generation of amps employing the likes of GaN and Purify technology and are garnering huge praises.  When Ralph at @atmasphere introduces a GaN amp and in some ways prefers it to his incredible OTL tube amps, well, that’s about as big of a statement I could think to hear about how far the newer technology has progressed.  To me, the handwriting seems to be on the wall where this is going as designers better learn to “tune” the latest digital components as they wish.  I think your prediction is absolutely panning out and in the next few years will come to fruition.