Class D amps seem poised to take over. Then what?


I am certainly biased by my lifetime final amp being a Class D. But I know that after 30+ years of development, Class D seems to be on a high plain. I know there are now many, many companies focusing on Class D and, maybe, a good handful already as good as it gets. My Class D amp is as smooth and beautifully musical as a great tube amp and as punchy and detailed as a great SS amp. I am satisfied and done with my search. A class D amp has effectively taken me off the amp merry-go-round. It’s about time after 50 years. And, for me, this Class D is a milestone. Will all other classes of amps fade away?
mglik
These companies that claim double wattage when impedence is halved don't give the actual 8ohm measurement, which is usually a lot higher wattage than their spec sheet has listed.
Our class D amps do 100 watts into 8 ohms and 200 into four. There is probably a slight difference due to the output impedance that causes the 200 watt reading to be inaccurate but its too low to resolve. But in reality the amp doesn't clip at 100 watts- it does so at 125 into 8 ohms but into 4 ohms it clips at 250 watts. So while your comment is true in some cases its not true in all cases.
You keep mentioning Wilson’s as being hard to drive, where does this come from?

For someone who "says" they’ve owned Wilsons, you are not very au fait or even interested in how they measure or behave, in particular the loading they present for amps to see.
While its true that the Wilsons have a low impedance in the bass (the Sophia and Sashas being the ones of their more recent lineup with which I'm most familiar) they really are reasonably efficient. When our MA-1 was hooked up to the Sashas (a friend of mine in town had them) the meters on the amp barely moved but there was plenty of volume. You have to take the drivability into account as well as the impedance. Our class D amps regard the Wilsons as a benign load.


Well..george has an MO of trying to cherry pick items to bolster his view.

The Wilson speaker Sabrina X was not the Wilson in the conversation, he read in a rag that the X could give some amps issues and decides to bring it into the conversation but the X has nothing to do with the Wilsons i own and he accused of being hard to drive. Historically Wilson's have the reputation of being efficient and easy to drive BUT require the best in electronics to make them shine.

Here are the Wilson's in question and george accused of being hard to drive. Page 77 has the specs. https://www.wilsonaudio.com/media/296/manual-alexandria-xlf.pdf
There are specs, and then there are specs. A fuller understanding helps with this primer I came across:https://darko.audio/2021/06/kih-89-mind-the-gap/

All the best,
Nonoise
Well..george has an MO of trying to cherry pick items to bolster his view.

You really need to get educated on this.
Look at the paragraph direct above your last post, even he back down on the flagship Wilsons I mentioned that a Class-D can't drive to their best. And he cherry picked the ones that can, (Sophia, Sasha ect)  because they have far easier loading that the Class-D won't be too taxed with🤦‍♂️
Stick with the facts. You claimed that i could not be getting good sound with my Class D and Wilson's claiming my Wilson's were hard to drive, don't muddy the waters.
They will not because people will seek out the best classic amplifiers and speakers when all the good new stuff is gone and find out that is where the best sound is anyway.

          Just for the record, I'm a big dog lover, including dingoes, or is it dingi?  However, most of my best friends are actually dolphins.

Later,
 Tim
Some mention "No Noise".. Where have you been?  My 1971 and 1996 Audire Fortes have no noise. Neither did my 1985 Audire model 2, 1990's Sumo, 1970's Phase Linear 400, nor my old $50.00 garage sale Adcom 535.  Well, actually I had to orient the Phase Linear plug with the correct prongs in their respective outlet holes.
Yep...reviews like this:

https://www.hifi-advice.com/blog/amplifier-reviews/power-amplifier-reviews/nuprime-agm-sta-stereo-po...

are definitely making me think about class D. I don’t think I need a replacement for my class A/B, but I’d add a D due to the fact that they are tiny and run cool and easily could fit with my current amp.
I’ve tried some high level class D amps and none have sounded better than my Class A Threshold amps. 
I purchased well regarded, highly recommend and reviewed Class D mono amps 1,000 watts of power and had high expectations but the Class D amps did not have the life, dimensionality, transparency and immediacy that my Class A SS amps had. With the Class D amps, the sound was flatter and much less engaging. So even though Class D amps may work well for many applications, IMO Solid State Class A amps produce better sound. And IMO, well designed tube amps sound even better than SS in terms of music. 
I honestly think the Benchmark amp is the ...Benchmark.

Sure, more power would be good, but because of how it's designed, bridging mono actually works and doesn't degrade performance anywhere, despite what some grumpy old know it all gatekeeper keeps spewing on this forum.

I have tubes, which i love for different reasons...have had icepower, hypex, A, A/B...However, lately i'm having a hard time NOT listening with the Benchmark. Having such a quiet noise performance, no matter what the haters say, is very special and makes the listening experience different, in every good sense of that word.

This is the first amp i've had where i'm not tempted to sell and upgrade, for fear i'll miss the sound too much. Hands down the best i've owned, and I will probably grab another soon.
Most of you know I have owned the EVS1200 for almost 2 years; dual mono based on AS1200 IcePower modules, but highly tweaked by Ric. During this time my system has undergone a number of cable improvements, plus new speakers (Emerald Physics 3.4s). I had been using optical cable between my Oppo 105 and my Audio Alchemy DDP-1 + PS 5 power supply.

For some reason (probably read one of the AG threads) I began looking into coax digital cables. Prices run the gammit from < $100- > $1000+. I contacted AA who offered either WireWorld ($$$-$) and Pangea ($$). I also looked at DHLabs, but decided to buy the Pangea. I bought a 1.0m SE ($49.95) and immediately was amazed how much better it was vs the optical. I reported this on my digital cable thread. Someone responded that 1.5m sounds much better. Why? I don’t know. For sure the others were $$$s for 1.5m, so I ordered it from Audio Advisor ($59.95). It performed much better, as mentioned, but how many hours of break-in before it really comes on song? Last night was day 6 of connection, but maybe 10 hours of actual play time. I listened to Lyle Lovett and his Large Band, followed by Bonnie Raitt, Nick of Time (I have owned them both for ~10 years): they both sounded quantum levels better than they ever did, no matter whether I had an all tube system, or all SS with class AB amps.

Cutting to the chase, ones digital connection could be why some have negative comments about class D

OMG I see they also have a Premier XL $149 for 1.5m, so I'm ordering it now

hth
I had two NAD Purfi units in my house and neither stayed long.
Ran hot, glitchy and hardware issues.


Modern Class D amps like those from Hypex or ICEpower (used in many high end brands) are simply excellent performers, musical ruler flat frequency response, SN numbers that other amps can only dream of achieving and they are respectful of power use and efficiency.

Heat and thermal cutoff is the real issue, as the power supplies can get excessively hot. Attaching finned heat sinks (ones with adhesive attach easily to flat heat shields) and providing sufficient air flow is crucial. Plus running hot kills performance. I've found AC Infinity fans with a Controller and a sensor work well and the speed is adjusted according to temperature. When the sound is not turned up the fans will be slow or stopped.
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Class D has definitely come along way.  From my thinking it really has just made its way to be able to compete with A, A/B and the other variants. 
I believe that we can finally believe it when someone says "its that good". ,   but we will still always have good Class A, A/B amps to consider.  Class D is no different than the others now.  A good design along with good parts make a nice amplifier.  
We finally just have another product to consider at any budget looking for bang for the buck or recently, even to compete with the best. 
You never know,  maybe Ralph @atmasphere  will design a switching tube amplifier. Ha
If you think class d is better than class a or class a b you better get your ears checked LOL they've gotten a lot better but they're still not as good.
When someone tells me that both Nelson Pass and Steve Deckert are now designing exclusively in Class D, I will consider more.  Until then I have 2 class D's and that is more than enough.  Love the operating temperature of class D.  Oh yea, I also love the operating temperature. 
I sold my Pioneer 70 D class amp. And recently listened Marantz Reference Series PM-10. All Class D amps have power and clean sound but lack of richness and soundstage.
I got my AGD class Ds just in time for 116 degrees here in Portland!
FWIW, these Class Ds are different from others.
@timlub 
You never know, maybe Ralph @atmasphere  will design a switching tube amplifier. Ha

We've already done that- been working on it for the last 4 years. We're in Beta production right now.

If you think class d is better than class a or class a b you better get your ears checked LOL they've gotten a lot better but they're still not as good.
Instead of checking your ears, it might be more fruitful to check a different class D amp and see if you still say that. Class D, like tube amps or traditional A or A/B amps, are all over the map in terms of sound. Some manufacturers have sorted out what works and care about it, and others have not or don't care- same as its always been...

Why does Class D attract these unsustainable blanket generalizations (e.g. @nseymour) while no one (well, virtually no one) would dream of making such universal claims w.r.t. class A or A/B?
The OP wrote:
My Class D amp is as smooth and beautifully musical as a great tube amp and as punchy and detailed as a great SS amp

If he believes this that’s fine - nice for him if it makes him happy.  I believe these perceptions to be (almost) completely subjective though.   
I’ll never own a D amp. Never. They’re built cheap. They’re all about low end sales. Tubes rule. There’s no shortage of tube amps to buy. I recently purchased a new KT-88 integrated, even though I already had one. So, as you see, I’d rather have two tube integrated’s than a single D amp. You lay down your money and buy whatever you want. No D for me.
Waiting until someone makes a class A class D

Some speakers like Magnepans need current 

I prefer 60 watts of class A to 1200 watts of class D
It will be interesting to see if manufacturers start to migrate away from less 'environmentally-friendly' amp topologies.  As executive leadership, and designers, become younger in these companies, they might make the decision to focus more on 'greener' designs like Class-D.  And, there is the possibility that environmental agencies start pushing for such a thing, just like has been done in the auto industry.  If tax credits are offered for R&D towards this, that will further incentivize companies in the green direction.

However, just like with cars - where there will always be 'classic/muscle car' enthusiasts -  there will also be Class-A, A/B, tube amp enthusiasts...and hopefully repair techs to service them ;) 

Of course, we're probably talking about decades, not years, but clearly there is momentum already occurring in this direction.
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I had an ICE class D amp.  I liked the sound but I'm a ham radio operator and it generated RFI which was picked up by my transceiver.  Went back to class A/B and now no noise.  
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I’m a ham radio operator and it generated RFI which was picked up by my transceiver. Went back to class A/B and now no noise.

You can check this yourself, get a portable "am radio" tune it around between 500-700khz "unmuted" turn up the volume, and go near your Class-D amps speaker terminals with it and even switchmode wall warts, and listen to it scream.
This is "what it looks like" on Stereophiles oscilloscope square wave shot (top pic) https://ibb.co/xgHv8dZ

But now Stereophile don’t show that pic anymore and filter it out with their AP test gear filters so you don’t see it, which should not be allowed, in my books as it's not representative of what comes out the amps speaker output.
They say it’s because the noise overloads the AP gear, but that’s bs because they didn’t use it years ago, with the same gear, and if it does then they should fix it not hide it.

Cheers George
If he believes this that’s fine - nice for him if it makes him happy.  I believe these perceptions to be (almost) completely subjective though.  
Not necessarily! It will sound like a tube amp if it has the same distortion signature and if you look at AGD's webpage for the product you'll see he published that. Not unlike an SET distortion signature... This is the sort of thing that's easily measured and heard.
Ahhh..Please reserve the term " Beta production" for software/mainstream tech ..NOT for the art of domestic audio....please
:)  Pretty funny
I liked the sound but I'm a ham radio operator and it generated RFI 
I had a class D amp in a subwoofer that interfered with FM reception! I got rid of it for the same reason. They're not supposed to do that and a properly built class D won't.


@atmasphere 

"We've already done that- been working on it for the last 4 years. We're in Beta production right now."

congratulations Ralph, I'm sure that it would be GREAT.  I'd love to beta test one.  
Man alive...
The more time i spend here the more it feels like a bunch of geezers trying to hang onto the old tech and talk about how $5k cables augment sound.

This might be the wrong place for me.
Man alive...
The more time i spend here the more it feels like a bunch of geezers trying to hang onto the old tech and talk about how $5k cables augment sound.

What do you think satellite TV comes from vacuum tubes. Satellites use vacuum tubes.
When Class D takes over, the earth will stop rotating and those magnetized by covid vaccines will be demagnetized.

The more time i spend here the more it feels like a bunch of geezers trying to hang onto the old tech and talk about how $5k cables augment sound.

This might be the wrong place for me.

For a friendly forum less obsessed by expensive gear, but rather heavy on vinyl, try the Steve Hoffman Forums. For a friendly one with a more costly slant, try Audio Aficionado.

@johnkent3  Lol. It certainly seems that way anymore.
I don't understand all the hatred for class D. I've had a number over the years and all were outstanding in some ways and needed improvement in others, just like any other amp. The same can be said for every tube amp, Class A and AB amps I've had over the years. No amplifier is perfect. 

Last night I was listening to my system and shaking my head in disbelief and loving every minute... with my class D amplifier.
Nothing in the audio world from the 1950s is much more than an antique.  The 2020 something tech changes everything, including the functionality of Class D amplification.  Earlier in discussion someone suggested that putting a tubed pre-amp in front will make it all OK.  I now run a Peachtree Grand X-1 hybrid integrated with a pair of 12AU7s in the pre-amp section.  This is supported by 440 watts per channel of Class D transistors and this is a marvelous machine for a home system.  Smooth, able to wisper and bang a gong.  I do not believe most (any) listeners would be able to detect a real difference.  
Good for cars and woofers.  300 kHz and under switching speed very noticeable on a moderate resolution system in a poor listening room.  I have 3 class Ds on my sub-subs (3 kW) also in all the cars.  Maybe they will get better for a good system. 
Class D will most likely take over if you have inefficient speakers that take tons of power like Electrostatics.  They are great in large areas, sub woofers because they are powerful.  I have heard some class D amps and they do sound good.  For some people probably a good choice depending on the room, speakers, tastes in music. 
Most people probably wont notice much difference.  Not if you have really good Speakers that bring out the best and the worst in music with a side by side comparison.  From that point it is what you like to hear.
My notion for class D got soured badly when I made my first exciting investment with a combo Integrated class D amplifier, streamer. It was small, cute,  powerful. It was dynamic. I was using 45 year old Crown A-AB+ 90WPC Amp, Crown Pre Amp. 
The line that crosses between a good system and a high end system which varies greatly depending on what it is and the investment.
I was getting ready for that old equipment to have a good butt whipping!  Uh, No, not even a close comparison.  Where the Old Amps were getting the details, Low Dynamics in the Trombone, Tuba crescendos giving balls to the lows, the Class D failed to reproduce any hint of fullness of the true tones of the instruments. Only Bass, sharp toned highs. Could have been a mismatch of my titanium drivers. I have 8" carbon fiber woofers. There was plenty of power from the 60W class D.  In fact it had more loudness that the old 90W unit and the class D driving the woofers hard.  Just the details I look for in music were not there.

Then, I decided to go get the best I could afford.  I went with a Tube integrated and it is in a league of its own compared with the Crown.  Crown was good, but nothing like the Tube integrated at half the power. I have learned from a friend that bought a pair of Red Dragon mono blocks.  He said they were very good, but the Shiit Vidars in mono sounded better on his Magnapans. I will never give up my tube integrated until I am in the grave. I have had it 6 months and it just keeps sounding better. Jaw dropping sound, detail, enough to make you laugh, cry, and dance with the wife.  :)
 
Class D amps have gotten better without doubt. They are performing on a level never thought achievable. But as good as they are in providing great transparency, detail, full midrange (vocals) and deep mind-blowing bass they still fall short in delivering the emotional aspect of the music. Not tapping my foot anymore. Fix that and I might consider retiring my Class A/B amp.
The only thing a class D amp is good for is driving a sub. Whom ever suggested class D amps are good for driving a hungry watt eating speaker like electrostatics never had electrostatic speakers. Don’t you know how revealing electrostats are? Who wants class D when you’re better off with a space heater class A, or a 100 watt tube amp. No way I’m giving up great amps for trash.
The SQ of my current Class D amp is the most emotional I have experienced without any other even coming close.
Maybe it’s the lack of distortion, having the right harmonic distortion, the transparency, the smoothness, the sweetness or the sheer musicality. To just say the sound is “wet” and not at all “dry” is an understatement.
I have certainly raved enough about my particular Class D amp.
But now feel there are, at least, a handful of Cl D amps on the market which have similar qualities.
I believe that within this decade Class D will surpass all other class amps and become the “benchmark” of quality Audio amplification.
Or it is just validation in your mind.
Not saying that as a disparaging comment I felt the same way with a couple of Class D amps till they showed their true nature.
I decided Class D is great for out on the deck, cheap and do not care if it gets wet.
Like what you like and be satisfied. If you are coming here for validation good luck with that.
Dead bodies attract dead bodies.


"Dead bodies attract dead bodies."
What does that even mean?
Also, it certainly doesn’t seem that anyone is looking for validation.
It appears to simply be a thread asking due to the advancement of the technology and subsequent sound quality, if class d is the wave of the future of amplification.
Does that mean you are addressing another member and not me, so you are denying me an explanation, or do you mean that you will not engage me in conversation at any time?
It is a rather cryptic statement. 
@mglik What is your current Class D? Not wanting to sift through this thread. Just curious.