Atma-Sphere Class D… Amazing

I am still waiting to see the measurements of this amp. Have they been published yet?

Whether or not it "outperforms" other class d amps can only be judged by the specs. Comments otherwise are purely subjective opinion which have no factual basis.

Personally, I commend the designer for producing his own design. So many just take oem modules and stuff them in a box.

I will say though that I will be greatly surprised if they perform anywhere near the products designed for Hypex and Purifi by Bruno Putzeys who has been designing state of the art class d amps for over 25 years and holds numerous patents.

When one can buy a complete 2 channel Purifi amp for $1000, one also needs to wonder about the cost of these amps in comparison to those made by Hypex and Purifi. I doubt they perform 5 times better and even if they did, the distortion of the Purifi is already below the audible threshold for most people. Why pay 5x the money for something you can’t hear?　Of course they may have a distortion profile that some find enjoyable, but that is a matter of taste, not pure performance.

Another spec sheet jockey. 

Purfi Amps and integrated shave never lasted more than 60 days in my system. 
 

I do like Nucor Class D had the Bel Canto ref 500 in my system and now one of my son at Grad School has them. He still enjoys the heck out of them.

@kuribo 

You sound as if your mind is already made up. I don’t understand your logic, you seem critical and dismissive of actually listening and judging what one would hear. Of course it’s a subjective process. How could it not be? You purchase these audio products with the intent of using them to listen to and enjoy music.
 

How would one determine if an audio product is suitable for them if they do not listen to it? What possibly will the amplifier measurements reveal to you that exceeds the actual listening experience? I don’t follow your reasoning.

Charles

@charles1dad

No, I am not "critical and dismissive of actually listening and judging", what I said was that there is no way to compare these amps to any others in a meaningful way when it is done on a subjective basis. Saying they "outperform" something else has no meaning to others when all it is someone’s subjective opinion. To be a valid statement of fact, it must be based on objective criteria. Seems this simple logical truth is just too much for some to handle.

One can’t argue with opinion, everyone is entitled to one. By all means listen but let's be clear- opinions are not facts. I am simply making that distinction.

Jerryg123, Marco1, you will not be disappointed in these in the least bit. I’ve got a few hours of hardcore listening time now. But, these  are truly world class as with Ralph’s OTL’s and preamps. I’d say if you like the M-60’s or Pass XA .8 and .5 series you’ll love these. Next weekend I’ll be doing some comparing with other amps. I picked these over buying Pass Labs .8 XA series amps.  I suspect I won’t be disappointed in my decision. I think either the Pass or the Class D I can live with. It’s going to be interesting to hear them side by side,  to see if one or the other is better. I want to listen to them longer. But I can say. The neutrality and realism I am experiencing is something I have never heard with any other amp. The accuracy to be true to the instruments and vocals is down right scary. I find myself walking into my living room expecting to see the band, vocalist or musician playing the specific  instrument. And am hearing details and micro-details  on recordings that I’ve never ever heard before. They also drive easy (105db 8 ohm) and harder loads (84.5-86 db 4 ohm that dip into the 2 ohm slightly) with authority without sacrificing the realism and accuracy and details. They don’t struggle at all driving bigger harder to drive Maggie’s.  The soundstage is huge and deep, with the speakers I’ve tried them on.  Like my MA-1’s The space between instruments and the separation of all instruments on the stage is also incredible,  probably as good as my MA-1’s. I have all NOS Winged C in MA-1’s and did a ton of tube rolling for the 6SN7’s to get them where they are. And have a lifetime supply of tubes since the OTL’s are so easy on them.  Best part these are not dry,  lifeless, class d’s I’ve that I’ve heard from a few other companies of higher end amps. Definitely the best Class D I have ever heard. Possibly the best amp I’ve heard under $10,000. But I’ll reserve that for the next comparisons. Not fair to say till I’ve had them side by side. 

Can't wait to pick a pair of these up. Summer is almost over and I've been struggling with the heat from my amps. These will be my next purchase for sure. 

I have a pair of these coming next week for evaluation at my home.

 Specs in many cases don’t mean best sonic characters. I’ve learned being in this hobby for 45 years that you don’t listen to specs. You listen to the sonic qualities of the amps. I am 57, and have been very fortunate to listen, own and have many different pieces of equipment. Some had great specs but were lifeless and dry to listen to. Adding to major listening fatigue. Not just my opinion but when we pass the pieces around to others they had all agreed. I stopped being a spec jockey many years ago. Listen to the audio gear and let your hearing be the judge. Specs are posted on Ralph’s website. 
 Am having some audio friends over today and night as well. I’ll let you know what they say about them. 
 

The spec argument has been around forever. I’ve seen so many threads on here over the past 15-20 years. It’s actually good entertainment at times. I give all gear a fair shake not dependent on specs. Actually I don’t look at specs anymore until after I’ve listened to the gear. 

Tinear123, I can’t wait to heard your impressions. I always love to hear what others think. And post the system you’re listening to them in. 

kuribo

I am not "critical and dismissive of actually listening and judging" ...

That statement is inconsistent with this:

Whether or not it "outperforms" other class d amps can only be judged by the specs.

And that’s how logic works. So while you're entitled to your opinions, you can't have it both ways while also claiming logic is on your side.

this simple logical truth is just too much for some to handle.

it must be based on objective criteria. Seems this simple logical truth is just too much for some

Okay, if that’s your position, that’s fine. I don’t believe that people find objective criteria too much to accept. Rather it is inadequate in determining the sonic performance of a given audio product. Anyway, thanks and I appreciate you sharing your perspective on this forum.

Charles

charles1dad

I don’t believe that people find objective criteria too much to accept. Rather it is inadequate in determining the sonic performance of a given audio product.

Exactly.

kuribo

I am not "critical and dismissive of actually listening and judging" ...

That statement is inconsistent with this:

Whether or not it "outperforms" other class d amps can only be judged by the specs.

And that’s how logic works.
 

No, it doesn’t. People can certainly listen and form their own subjective opinions as to whether or not they like amp A, or prefer amp A over amp B. As I said, everyone is entitled to their opinion. Opinions are not facts.

When someone says amp A out performs amp B, they are making an objective statement as there are parameters that can be measured and compared objectively. An amp is by definition a device that takes a small signal and outputs a larger version, by most standards, the more accurately the signal is enlarged, the better the amp’s performance. We can certainly compare the input to the output and measure the differences, and from those differences make objective comparisons.

Many people actually prefer an amp that adds certain distortions to the output. Some don’t. Subjective preferences don’t have to, and often fail to, align with the actual objective performance.

@pstores 

Thanks for all the useful info on the sound of the new A-S Class D amps. As you continue to listen and compare these amps to other high quality amps, please provide some additional comments on their ability to convey a fullness and richness of tone, especially in piano, voice, acoustic guitar, and upright bass. When I hear about an amp's ability to convey great detail and transparency, I worry that the added detail may come at the expense of a natural fullness of tone. I've heard this effect in several good quality interconnects that provide excellent detail but don't have quite enough "meat-on-the-bones" in the upper bass and midrange to provide the balanced sound I like to hear. Any additional comments in this area of performance would be much appreciated. 

Okay, if that’s your position, that’s fine. I don’t believe that people find objective criteria too much to accept. Rather it is inadequate in determining the sonic performance of a given audio product. Anyway, thanks and I appreciate you sharing your perspective on this forum.

What are objective measurements missing, other than subjectivity?

Could it be that while we can objectively measure how well the output compares to the input, we simply can’t account for taste? Is it so hard to comprehend that people’s tastes can differ and that some people just happen to prefer some distortion added in? Why must we assume that there is some mysterious unknown physical phenomena that just can’t be captured by modern science inherent in audio equipment, be it an amp, cables, or whatever, that has to exist to explain the tremendous range of opinions about audio gear when the simplest explanation is that the phenomena isn’t in the equipment but in ourselves?

Is the need to have our opinions validated, confirmed and shared by others so great that we need to invent baseless rationales in order to be "right"? Are we so insecure that we need to seek out the opinions of others rather than be satisfied with our own subjective impressions? Amazing, isn't it, how people will take to heart others subjective impressions of audio gear as if there is truth in them for themselves but wouldn't ever think of letting someone else season their steak or order their meal for them at a restaurant...

It really is ok to just like how something sounds, regardless of whether or not it is objectively superior. And it’s ok for others to not like it.

@pstores 

I am looking forward to the additional listening impressions from your audiophile/music lover friends. Should be insightful and certainly fun.

Charles

Is anyone running a DAC direct into the Atma-Sphere Class D mono block amplifiers or is a pre-amp required? From my past previous experiments, I believe a preamp is needed to help the music sound natural, clearer, and engaging. I believe that a preamp helps makes the music more engaging and sounding better.

I do not know. Does the Atma-Sphere Class D mono block amplifier design help them sound great without an preamp? Your comments are required. Thanks......

HGEIFMAN, I can give it a try with my Bel Canto DAC tomorrow. It has a linestage preamp built in. 

@ddafoe   …”I find the monos offer a maybe slightly less 'meat-on-the bones', but a wider soundstage, good depth but maybe not quite as deep, but offer a blacker background and ultimately allow me to hear in and around the instruments just as much”
 

Really interesting observation. Exactly identical description of the difference between the Audio Research REF 160m monoblocks that I have been comparing to my Audio Research REF 160s strereo amp. To the word… exactly how I would describe it.

@kuribo “Opinions are not facts”

Opinions are certainly factual in the case of audio and sound preferences. 100% factual. In this hobby/passion of audio we must first recognize this one undeniable fact. How something sounds is 100% subjective and tied to one’s unique ears, room, associated gear and preferences. In fact, the only absolute truth of how something sounds, is found in one’s actual experience with the piece and their resulting opinion. That’s it. 

Opinions are not facts. Sound preference isn't a fact, we don't get to make up  facts. 

We can certainly compare the input to the output and measure the differences, and from those differences make objective comparisons.
Many people actually prefer an amp that adds certain distortions to the output. Some don’t. Subjective preferences don’t have to, and often fail to, align with the actual objective performance.

@kuribo But you can’t tell how an amp really sounds just by looking at measurements either.  You can have two amps that measure similarly but sound completely different.  Why?  Because we don’t have near enough the measurements that can measure everything that has an impact on sound.  Case in point, you can buy an amp and upgrade capacitors, resistors, etc. and the measurements won’t show any difference but the sound can change significantly.  Measurements are useful as a piece of assessing performance but are FAR from being able to sufficiently describe the complete sound of a component. 
 

What are objective measurements missing, other than subjectivity?
 

Wait…ASR is calling — they need you back there ASAP!  Go!!!

Opinions are factual in the context here. They are factual because of the 100% subjective nature of the topic. Some just can’t handle the truth it seems. Measurements are simply data points. They have nothing to do with the reality of sonic preferences and resulting opinions.

We just have to accept the sonic preferences and experience based opinions as truth for that person. 

So IMHO, after some in depth listening today so far. I switched back to my MA-1’s. I do prefer the MA-1’s. I like the attack and decay of the MA-1’s better. I like the depth and fullness of acoustic instruments better.  It’s a warmer presentation you’d come to expect from tubes. Although I don’t believe the M-60’s would keep up to the class d. I also believe if someone likes a nice SS Amp like Pass XA 60.8 they may prefer the Class D over the MA-1’s. Also there are a few things that I do like about the Class D over the MA-1’s. To be fair though I rolled a lot of Tubes in my MA-1’s looking for a certain signature. And that’s what I am used to. And the MA-1’s I have are 4 times the cost. So I’d hope they were better. 
  With that said….. Clarity, neutrality and especially realism is where the class d shines. It definitely stays true to the music, instruments and  adds a higher level of micro-details. I hear a few more things in the class d. I am going to roll in some tubes that aren’t as soft and warm in my Ma-1’s. Anyway…. I’ll see what others have to say today and tonight. Hoping a friend can bring over his fully optioned M-60’s soon. I know when I moved up to the MA-1’s it was significant. 
 

JMHO…..

Opinions are not facts even in the context here. All you have with any 100% subjective topic is subjective belief, the only "fact" is your belief of your preference and opinion. Facts are universal not individual. 

Here's a fact.

How sound becomes hearing.

A fact is simply collected information and not universal. It is a fact that we each hear differently and own different systems in different rooms. It is a fact that we as unique human beings have varying sonic preferences. This is all accumulated information and fact. Our opinions flow from these differences.

A-S Class D vs. a highly regarded $3k SRP stereo amp with possibly the all-time lowest SINAD specs, only about 13#, not class D, a patented circuit, released around 2015 and winner of a ton of awards.  The stereo amp had audibly more musical detail.  For unknown reason and there's no way to prove this true or false, I got the sense the stereo amp was more "accurate" or linear; yet in no way did this last point make me favor it.

IMO the A-S Class D had blacker background, the stage was audibly bigger in all 3 dimensions and had an upbeat, more musically satisfying presentation.  Images had more body/density and more air around them.  In the AB test the stereo amp simply sounded more sterile and mechanical.  Like a sharply dressed, quick talking boy that arrived to date your daughter, but he just seems a little disingenuous; he makes you question his motives.  Why does he have such a perfect exterior?  Is it an act?  I want to get to know him better, but he never lets his guard down.    

Overall I favored the Class D significantly more than the stereo amp.  Yes, the Class D costs more but I suspect most people that can afford the stereo amp can stretch funds and/or save a little longer for the Class D, which seems like even better value than the stereo amp considering the awards heaped on the latter.  

@kuribo But you can’t tell how an amp really sounds just by looking at measurements either.  You can have two amps that measure similarly but sound completely different.  Why?  Because we don’t have near enough the measurements that can measure everything that has an impact on sound.
 

No, you can't tell with any certainty how an amp sounds strictly from measurements but you can tell certain things about it's performance, whether it adds distortion, how much, where and when, how it's performance varies with frequency and load impedance, etc.

Sound similarly to whom? To everyone? Doubtful and not realistic. There are too many biases and other factors that enter into subjective impressions.

What measurements are we lacking? Please explain what it is that we are not measuring. Just because something sounds the same to you doesn't mean it is the same, or that it will sound the same to someone else. Of course, there are things humans can't hear, and it is possible this lack of hearing can cause things to "sound" the same, if the differences are beyond audibility.

I ask again, why does it have to be a lack in what we can measure, why can't it be a difference in subjective perception?

 

Opinions are not facts even in the context here. All you have with any 100% subjective topic is subjective belief, the only "fact" is your belief of your preference and opinion. Facts are universal not individual.

Right on.

Daniel Patrick Moynihan — 'You are entitled to your opinion. But you are not entitled to your own facts.'

We just have to accept the sonic preferences and experience based opinions as truth for that person.

That’s my point. If we want to compare anything meaningfully and rationally, we have to argue the facts, not opinions. Measurements, assuming they are done properly with functioning equipment, are not opinions- they are objective fact. How one chooses to interpret them can become objective and a matter of opinion.

How something sounds is 100% subjective and tied to one’s unique ears, room, associated gear and preferences. In fact, the only absolute truth of how something sounds, is found in one’s actual experience with the piece and their resulting opinion. That’s it.

Exactly. What others think they hear, while truth for them, doesn’t mean it is truth for anyone else. This is why all the fluffy talk about "deeper body", "better tone", "blacker background", etc. is utterly meaningless to anyone other than the speaker, yet people continue as if it actually means something to others...

The fact of the matter is, measurements don't even begin to inform one of how something is going to sound, just that it will meet the low standards of conventional wisdom.

All the best,
Nonoise

The facts as I see them are most here would like you (you know who you are) to stop blabbering. 

The fact of the matter is, measurements don't even begin to inform one of how something is going to sound, just that it will meet the low standards of conventional wisdom.

Someone doesn't know much about measurements. They may not tell you if you will like it, but they certainly can at least point to how something will sound based on the distortion spectra. Just ask Ralph, who designed the Atmosphere amp under discussion.

Newton's laws were fact until Einstein came along, so some facts aren't universal.

Newton's laws were fact until Einstein came along, so some facts aren't universal.

Not facts, theories.

noske..................................Peachtree GAN 4000 over the ATMA any day for the $$.....Atmasphere overpriced for their sound !....Better Music for thousands LESS....sorry Bro.

The facts as I see them are most here would like you (you know who you are) to stop blabbering.

Yea, it is sad to see an enjoyable GaN related thread derailed yet again; this one didn't do much better: https://forum.audiogon.com/discussions/gan-amps-peachtree-or-lsa-voyager

Can anyone spot the common variable between the two threads?  It kind of reminds me of the classic SNL Debbie Downer skits :)

Peachtree GAN 4000 over the ATMA any day for the $$.....Atmasphere overpriced for their sound !....Better Music for thousands LESS....sorry Bro.

Atmasphere may indeed be overpriced, that's a matter of opinion, but at least it is properly designed and doesn't have load varying frequency response (a fact) like the Peachtree. That failing was addressed 25 years ago by competent class d designers (fact). Really unthinkable that a modern class d amp would have this shortcoming (opinion).

@ozzy62 

+1

Yes I have......Atma.....is not worth the $....... Peachtree is a Great price to performance  option...Sorry all you screwballs.. Save $ and enjoy the MUSIC !

@mbmi I have not heard the new Class D offering…but I do believe Ralph has earned the respect of most of the rational audiophile community whether they purchase Atmasphere or not. I’ll call you on your claim that you heard the Atmaspere class d amp and find the Peachtree superior, even dollar for dollar. I dont believe you.

Someone doesn't know much about measurements. They may not tell you if you will like it, but they certainly can at least point to how something will sound based on the distortion spectra.

Sounds like someone is having fun with semantics at this thread's expense. 

"They may not tell you if you will like it" is pretty much the same as "don't even begin to inform someone of how it's going to sound" with the difference being the tense and the taste of the individual.

"...certainly can at least point to how something will sound based on the distortion spectra" is another way of saying "meet the low standards of conventional wisdom." albeit from different points of view. 

All the best,
Nonoise

Well I can say Peachtree when in a quality system you’ll hear the pitfalls of them.  The more revealing system the more pitfalls you’ll see. They are a dry,  lifeless Amp. Lacks in details and is very fatiguing. They won’t even be close to Atma-Sphere Class D. Maybe 40% of the Atma-Sphere at best. Guessing there is some degree of Atma-Sphere haters here. Comparing the Peachtree to the Arma-Sphere is like comparing a Ford Pinto to a Mercedes 380SL. JMHO…. 
 

So in the reviews today and tonight. The Tube guys liked the MA-1’s better. The  Pass guys like the MA-1’s better for the Blume, Soundstage and space. But liked the Class D’s over all. As I suspected would happen. My MA-1 tubes are very laid back. If I put different tubes in there maybe a different response. The Pass guys have the XA30.8, XA60.8, XA250.8  x250.5. All very impressed.  Will be putting the class D’s into their systems next for an comparison. A lot of comments like these are only how much?  One comment “maybe the best amp they’ve heard under $10,000”. All agreed at $5400 they are a steal for the sonic qualities. And all agreed there is a degree of give and take between the MA-1’s and the Class D. Like I said next is to put them into others systems and see how they do in various systems. All are world class audio systems. 

pstores,

Have you heard (in your system) the new Peachtree GaN 400 or are you referring to an older Peachtree amp?

hgeifman-  I've had the new Atma-sphere class D monos in my system for exactly 3 weeks today not using a pre-amp and they sound fantastic.  I researched whether or not they could be driven by my Cary DMS-600 before I took the plunge.  They are replacing my tube amp.  I've not used a pre-amp in 11 years so couldn't tell you whether a pre-amp would improve.  The tube amp I ran was a Music Reference RM10 MkII which was ideal for running direct or with a passive pre.  The monos sounded good out of the box but after 3 days came alive.  I'd really like to try an Atma MP-3 with them but it would be a rather expensive experiment.  I was told by Cary that the DMS-600 is truly balanced so I'm not sure I would gain anything.  My system is posted here.  Contentiousness abounds, LOL!  Now back to listening to music cheers.

Sounds like someone is having fun with semantics at this thread's expense.

Quite the contrary.

From the distortion spectra, research has shown that certain distortion profiles will produce certain "sound"- compare the distortion spectra of many tube amps vs ss a/b vs class d and you find many describe the tube sound as "warm", "rich", "lush", etc. Class d as "neutral", "clear", etc. Certain harmonic profiles lead to similar perceptions, thus, from the measured performance, we can indeed make certain predictions on how an amp will "sound". Will everyone "like" that sound? No. This isn't semantics, it's psychoacoustics, an admittedly soft science.

@ricevs 

+1 on your comment about which Peachtree amp

My own extensive experience with my Voyager GaN 350 (said to be the same as the Peachtree) is that is chameleon-like: a change of vibration control devices (the OEMS suck the life out of the leading edge, overall softening the sound), changing power cords or interconnects, or anything in the chain is readily heard. Another huge factor is whether the music is being played at the PROPER volume