Atma-Sphere Class D… Amazing

Well, if this is the case, yes...

@soix

Here you go:

"Conclusions
It was just a few years ago that people scuffed at class-D amps not being very clean or good for audiophile use. How the situation has changed. First with Hypex modules and now with the Purifi 1ET400A. Audiophile myths are shattered with use of large amount of feedback and high bandwidth to produce an amplifier which brings transparency to anything you throw at it.

Importantly, the 1ET400A does all of this while producing a ton of power and staying cool and efficient to boot.

There is a subjective aspect to measurements that doesn't come across in the graphs. When I run these tests with switching amplifiers, I often watch the analyzer struggle to get reliable reading, or there are jumps and glitches in measurements. None of that was here. The amplifier basically acted like a traditional class AB amplifier. Indeed, I measured it with and without my AES-17 40 kHz filter and the analyzer was happy both ways. This is when I know there is quality engineering that has gone into design of this amplifier.

Overall, it is my pleasure to strongly recommend the Purifi 1ET400A to DIY and OEM manufacturers."

Who’s the moron?

@jjss49, I am too far from electronics, but a common sense says that there may be something rational in some critical suggestions. Of course, someone like, you, better understanding the technical background, may really be true that such "suggestions" have no technical soundness. But, at least, I think that they do not harm. So, what is the point in the sarcastic notes?  

…

@kuribo Ok, I know I’m feeding the troll here, but please share where one can get SOTA sound for $1000.  I can’t wait to be educated.  Moron. 

He has to be referring to the Hypex, as the purifi are more like 2k$.
But the Hypex are really pretty good.

To me they define the bottom separation level, of the Class-D “high end”. 
 

@jjss49 

sell products to retail customers... you just get used to alot of random noise from purported know-it-alls

Clearly one need not be selling products at all to be subjected to a lot of random noise from purported know it alls.

Value picking seems to be easier when applied to established technology. Class D amp tech seems to in an evolutionary trajectory.

Current state of the art class d has performance with distortion at the limits of human hearing. Purifi, a leading class d amp company, is focusing their attention on drivers these days because in their opinion improving their class d amp has reached the point of diminishing returns. Speaker drivers are the weak link in the chain, thus I wouldn't worry about buying a state of the art class d amp only to have it materially improved in 2 years. Besides, one can get the state of the art for around $1000 these days.

If that is so either the opamps were really terrible or the designer didn't know what he was doing! With any module you really don't need a lot of gain, so why would decent opamps affect the sound?? Answer: if the buffer is properly designed and if decent opamps are used, they won't.

Plenty of people have bought in to the "everything matters, everything has a sound" mantra. As I am sure you are well aware, audio people can be quite insecure and easily influenced by the siren song of other's wacky claims. Just look at all the audio voodoo on the market- if snake oil could only be refined into gasoline we would have $0.25/gal gas again.

 

What a sad train-wreck of a thread.  I feel bad for Ralph having to try to educate a bunch of keyboard warriors all because someone said something nice about his gear.

My conundrum. I'm warming up to Class D. Actually, more the opposite as heat avoidance is the main reason for seeking out a Class D amp.

My problem is that I'm a keeper. I'm not a component every year type of guy. More like every decade.

So there's an obvious tension between getting the value oriented "giant killer" and the point of diminishing return "SOTA".

Value picking seems to be easier when applied to established technology. Class D amp tech seems to in an evolutionary trajectory.

Ralph's and a few other's SOTA are so tempting.

But will the saying that today's SOTA is tomorrow's **** apply to my Class D purchase? On the other hand,  life is short.

I agree with that whenever SQ can be affected, but making thick chasis just to  protect the amp during the shipping seems to me unreasonable - just pack it well! 

We've always packed our equipment well to survive FedEx/UPS treatment. But experience has shown that even though its packed well, the chassis can be deformed by the mounting bolt for the transformer if the transformer is heavy enough and the chassis thin enough.

These are the claims of customers- they prefer the "sound" of certain op amps over others, not mine!

If that is so either the opamps were really terrible or the designer didn't know what he was doing! With any module you really don't need a lot of gain, so why would decent opamps affect the sound?? Answer: if the buffer is properly designed and if decent opamps are used, they won't.

If they can ’tune’ the sound just by changing opamps they are either using really terrible opamps or don’t know what they are doing!

These are the claims of customers- they prefer the "sound" of certain op amps over others, not mine!

I would think that a module with a high PSRR would reduce any deleterious effects of the smps, at least that is what Bruno claims with his modules. Based on their measurements, it seems to be true.

@atmasphere , I agree with that whenever SQ can be affected, but making thick chasis just to  protect the amp during the shipping seems to me unreasonable - just pack it well! 

I think what @kuribo says is very reasonable, and this is not something in  what he can have some personal interest. If you manage to lower the price of your product (without sacrificing SQ) , given its good or even outstanding sonic characteristics, your product will become much more competitive and you will be able to sell much more of them having higher overall gain, talking in pragmatic terms, unless you wish to have a product for a very selected amount of people. 

Indeed, those marketing Hypex, Purifi, and several other class d amps using the modules of others can "tune" the sound through the input buffer op amp choices

@kuribo If they can ’tune’ the sound just by changing opamps they are either using really terrible opamps or don’t know what they are doing!

We’ve had the idea of a SMPS meant for the amp for a couple of years. That’s not a trivial design project although its certainly an one than the module itself was! Of course we looked at available SMPSs including those meant for audio, but again we ran into not only performance (which impinges the sound and performance of the module) and protection issues but also cost issues! If we make it ourselves then we solve three problems at the same time. In the meantime the toroidal supply is less expensive, works right and we have the right protection although we need a more expensive chassis to support it. IME though, that chassis helps with the mancave/WAF issue. In my case this means that I don’t have to have a mancave to run my stereo (although I do have to be careful about cargo shorts); it can be in the living room without inciting ire. Ya picks ya poison I suppose.

I should also mention we're concerned about noise. For example Bruno uses a current pump to create lower voltages for opamps and the like. We found that is noisier than using a more expensive supply for the same task. As a result the amp puts less noise on the AC line than most tube amps.

@twoleftears

This really is rich.  First we have ricevs telling Ralph how to redesign his amps, and now kuribo has a go.

Meanwhile, Ralph is model of restraint and superhuman patience.

So we didn’t skimp on the power supply or the chassis. We just built it to proper engineering standards without cutting corners. IMO one of the reasons you see such variable comments about how Hypex and Purifi amps sound is because of how they are executed.

Thanks for the insight. Indeed, those marketing Hypex, Purifi, and several other class d amps using the modules of others can "tune" the sound through the input buffer op amp choices. I suppose it is a clever marketing technique to appeal to different tastes, rather than offering any color the customer wants, as long as it’s black. Of course most of them degrade the performance of the amp modules to some extent, but as we can see here, there are those who aren’t concerned with high fidelity to the input signal. Other such differences, like type and style of case, input mains filters, mounting configurations, etc., surely do vary widely, from head scratching to immaculate. No doubt these differences play some role in the final result as well-how much, I do not know.

No doubt with the weight of the transformer you would need a stout case. I suppose that can certainly add to the costs, though it is hard as a consumer driven by performance to justify spending 3-4 times as much as a competing product for things like a dealer network and a stouter case, neither of which in my opinion makes it "go faster". You might consider using a smps, a lighter, cheaper case, and offer your amp for half or 1/3 the price. Surely there is a sizeable market at the lower price point.

Again, appreciate the reply.

@kuribo The cost has to do with how the equipment is marketed. We use a dealer network and have worldwide distribution. That requires that we have it priced accordingly. Dealers can be quite valuable because they can provide support!! FWIW if we were to use a Purifi or Hypex module, the amp would actually be more expensive than it is now due to the markup we would have to pay on the module. The cost of the chassis, built extra rugged so it will survive abuse in UPS while being built in limited quantities, is a big reason the amp is more expensive. The funny thing here for me is for decades we were always docked on cosmetics. I was always resisting installing a 1/2" thick front panel on our stuff since it would have raised the cost so much, but that is what our competition has been doing all this time. And we still don't have the 1/2" panels!

So we found a way to limit that cost a bit, but the simple fact is that if you do this stuff in the way that we are (the chassis is formed of 3/16" aluminum for example, to prevent deformation with the weight of the power transformer) its simply more expensive. Now if we were to use a SMPS it would allow the chassis to be cheaper, but our research has shown that if you really want the amp to perform the way it should, the SMPS will be custom built for the job. Otherwise it will current limit or other such nonsense and we certainly experienced that!

So we didn't skimp on the power supply or the chassis. We just built it to proper engineering standards without cutting corners. IMO one of the reasons you see such variable comments about how Hypex and Purifi amps sound is because of how they are executed.

He did state that he likes Purifi and Hypex, and that they also have published specs and graphs.
So I do not think it is out of line to ask for the graphs.

Being a fanboi of those brand does not automatically exclude one from liking, for instance, Atmasphere or Benchmark. It seemed more like “he has no objective proof that he should like them,” which if that is really what he means, then I cannot find a cogent argument to oppose that view. And I like them without an objective and rational reason to do so.

Hypex, Orchard, and Purifi are some of the current state of the art performance wise. The publish detailed measurements that give a great deal of insight into the abilities of the designer, the behavior of the product, and how the amp will play with other components. Additionally, they outline and highlight the performance envelope for users. Clearly these companies believe there is some value added by documenting the performance of their products and I for one agree. All properly engineered commercial amps are rigorously tested and measured by their designers so this is not asking for anything they haven't already done. I fail to see any legitimate reason to not share such data. Not everyone can or does find value in such information but that is no reason to piss and moan about those who do. I happen to appreciate products with state of the art performance and elegant engineering, both of which often go hand in hand with transparency from the manufacturer.

 

No I am running Cullen Cables Power Cord. Hope this doesn’t open up a can of worms…. I use them on everything

No it is all good. I appreciate your post.

I just assume that it doesn’t matter a whole lot, and it seemed like it would be good to have in here.

If people like their off the shelf Hypex or Purifi based class d amps then they need not look for a superior sounding amplifier.

He did state that he likes Purifi and Hypex, and that they also have published specs and graphs.
So I do not think it is out of line to ask for the graphs.

Being a fanboi of those brand does not automatically exclude one from liking, for instance, Atmasphere or Benchmark. It seemed more like “he has no objective proof that he should like them,” which if that is really what he means, then I cannot find a cogent argument to oppose that view. And I like them without an objective and rational reason to do so.

And let’s be a bit realistic here; we are talking about the best in Class-D…all of which are very good by most standards whetherb they are objective or (unsighted) subjective.

It is not like being about as good a Purifi and Hypex, as good, or a bit better, is very different… they are all very modern amplifiers showing the best of the topology.

and I thought that @pstores posted that he had also tried Purifi and either Hypex or Benchmark, so I am sure that the graphs are likely nothing to be embarrassed about.

@niodari no he is just brow beating Ralph because he loves his new amplifiers.

Please! 
 

Have a good evening. 

@holmz

No I am running Cullen Cables Power Cord. Hope this doesn’t open up a can of worms…. I use them on everything. 

@niodari 

+1

@juanmanuelfangioii , allow different points of view. Do you think that it would be better if everyone will repeat the same? It is good to have different opinions and some criticism. By the way, @kuribo never said that he does not like Atmosphere class d. 

Folks,

I find it funny that you call names on a trolls. Why won’t you stop responding to whoever trolls are on this thread! Does it hurt your egos?

No, I am not sorry to be rude at this point; but let it go and don’t feed the trolls.

Okay I will do just that as you are a waste of bandwidth. 

@juanmanuelfangioii

No one is forcing you to read my comments. You are free to ignore them.

Sorry if I am not cheering loudly enough for you fanboy. I deal in facts, not blind adulation. Show me the money.

@kuribo you should just switch OFF!

Ralph has built some great audio equipment and given us all the gift of his knowledge and his wonderful engineering talent. 

All you bring is the same old crap about crap, your posts are like that gerbil running on the wheel, they go nowhere. 

@juanmanuelfangioii

Maybe switch to decaff.....you seem way too stressed out about nothing.

+1 juanmanuelfangioii

@kuribo is a broken fricken record. You are like that old junkyard dog that gets a hold of a bone and will not let go.

Let it go, you are truly one dimensional. 

I would rather hear an explanation from the designer/producer himself rather than the ruminations of a 3rd party.

THEN CALL HIM !!!
EMAIL HIM!!

JUST LET GO or better yet just go. 

Because it costs money to build a better mousetrap.

We have no proof it is indeed "better", whatever that means.

I am sure other manufacturers provide after purchase service and employ people as well...

Other than that, I would rather hear an explanation from the designer/producer himself rather than the ruminations of a 3rd party.

PS. Since SS cannot be, SW. S comes in mind

What about "Switching state" (class D) amplifier?

It would be even nicer if he addressed how his product differed from competing class d amps in performance and what a consumer gets with his product that justifies the price of 3-4 times that of competing products.

Because it costs money to build a better mousetrap. If people like their off the shelf Hypex or Purifi based class d amps then they need not look for a superior sounding amplifier. They found their version of great. There's also a four plus decade track record of excellence which also means service after the sale, a good living for those who work there, etc. 

@gdnrbob maybe ask @atmasphere what power cord to run on them?
I assume that @pstores is using what Ralph sent??

One of the reasons I have bought Atmasphere's products is that Ralph can clearly and simply describe why his equipment works as good as it does.

I agree, it is nice that he takes the time to discuss his products. It would be even nicer if he addressed how his product differed from competing class d amps in performance and what a consumer gets with his product that justifies the price of 3-4 times that of competing products.

One of the reasons I have bought Atmasphere's products is that Ralph can clearly and simply describe why his equipment works as good as it does.- As well as how we perceive sound.

Bob

Unfortunately, "Job" is already taken as an amplifier name.

(And that's pronounced with a long o.)

Agree with @jjss49 and ​​​​@grannyring .

Ralph is right that many do make class D "amplification" synonymous with digital and they are not.

Charles

+100 @jjss49

Ralph is a man gifted with patience along with his many other talents! 

@atmasphere 

ralph, you are just a prince, you are kind, you have endless patience

kudos to you

So yes, Class D is more accurately referred to as a "switching amplifier" rather than a "digital amplifier" but things get blurred when binary quantization is involved as binary quantization is at the heart of digital too. 

@fsonicsmith The on and off states of a digital word have meaning- IOW the arrangement of the bits create a word which represents a voltage. In a class D amplifier the on and off states have no such meaning. When the term 'digital' is used, its assumed to not be analog. Despite being a switching technology, a class D amplifier's functionality is entirely analog. 

There's no intention to 'cut you down' or anything like that! Whenever I see anyone use the term 'digital amplifier' while referring to a class D amp, I feel its important to clarify since this is such a common misconception (or misuse of terms). If you do a search, you'll find I've done this on this site dozens of times over the last several years; please don't take it personally.

@kuribo negative innuendo may not be a good strategy for it.

It's not a strategy, it's an observation.

Indeed it would be nice to see the freq response versus load, the distortion spectra, etc....Too bad this info hasn't been forthcoming. Not sure how to interpret that...

@kuribo negative innuendo may not be a good strategy for it.

Well, I just put in my order for a pair of Atmasphere Monoblocks.

I was not considering Class D amps, but when Ralph embarked on this new path, I have been very interested in giving them a try.

And, as many know, I am a Vandersteen guy, so owning a Time and Phase Correct speaker meant using a Zero Feedback amp for optimal results.

Atma's new Class D amps use feedback, but Ralph believes that Class D allows for more Gain Balance Feedback that conventional amp do, and without the negative effect of adding high ordered harmonics.

(I hope I got this right Ralph...)

Bob

B

So I do not think that it is out of the question for Kurbio to ask for objective proof. Ralph has been talking about the distribution of the harmonics for a while, so to see it would be dandy way to objectively show some of what makes them sound good..

Indeed it would be nice to see the freq response versus load, the distortion spectra, etc....Too bad this info hasn't been forthcoming. Not sure how to interpret that...