Atma-Sphere Class D Mono blocks

[Gregadd]

what s the price? it seems as though Ralph has offered a return for in home evaluation.

 

[Holmz]

what s the price? it seems as though Ralph has offered a return for in home evaluation.

$5400/pr

I’ve come to understand that there are 2 categories of amp that have the potential to float my boat. One of the key ingredients of the first type is that it has extremely low levels of distortion. I have some of Tom Christiansen’s Neurochrome amps. They are the most neutral and transparent sounding amps I’ve ever heard and that kind of open window on the music has its own set of charms. These DIY amps would embarrass many commercial amplifiers costing orders of magnitude more. The Wolverine amp recently designed by a group of enthusiasts on DIYA may pull off an even better disappearing act, if that’s possible. (I have the PCBs to build the amp.)

The other category comprises amps that have a particular distortion profile, specifically one where the 2nd harmonic is dominant and the higher order harmonics successively decrease in amplitude. I believe the BBC did some research in the 40s or 50s that concluded that this sort of profile was favoured by many test listeners. Jean Hiraga conducted his own experiments and reached a similar conclusion. You’ll find modern day designers who also subscribe to this school of thought. Hugh Dean (AKSA) designs all his amps with this goal in mind and Nelson Pass has even designed a DIY distortion generator which you can use to add variable amounts of 2nd and 3rd harmonic distortion to your audio chain.

So Ralph’s comments about his amps resonate with me and I’d certainly like to hear them. Not sure that’s possible in the UK though . . . .

^100%^

I currently have a tube pre and a tube power amp.

But I have heard some of the Purify based amps with the Purify low distortion drivers, and the “quietness of the sound” was astonishing.
It was playing at a measured 90dB(A) with peaks of 100+, and one could not hold a conversation… but they did not sound “loud” with the low amount of distortion.

It was really a quite pleasing presentation.

Sort of like how Triode is a bit subdued compared to UltraLinear… One can like the sound of UltraLinear, but the Triode operation is seems a better sounding with sparse vocals and piano.

As @iansr pointed out in paragraph 1.
But he pointed out paragraph 2 the distortion profile, and both my old preamp and newer one have the distortion profile that he describes.
Hence I am heavily leaning towards coupling the preamp to the speaker using the low distortion of an Atmasphere, Purify or Nuerocrome.

 

[the sound of Tao]

Yep - there's far too much of that regarding Class D. Many won't even consider the notion. More fool them.

Hi Ralph… I didn’t say you had said this… this is the kind of comment that has been made in the thread that I was referring to.

 

[DonH50]

Unless the comparison is blind perceptual bias/prejudice will likely color the result (either way, pro or con class D).

 

[Gregadd]

500-hour warmup is approximately 20 days. If leave it on24 hours for the full 20 days. That means 10 days left on a 30-day trial return. That is tight but manageable.

Unless the comparison is blind perceptual bias/prejudice will likely color the result (either way, pro or con class D).

And a blind test will be inconclusive, or consistent with chance. Oh, but in this case, we don't' want to prove everything sounds the same. We want to prove one is better. Otherwise, why bother. I am assuming that is the two hypotheses. Class D is better than tube. Tube is better than Class D. That is, if history is any judge.

Sorry Professor Don, this time I am being a smartass. I don't think anyone is suggesting a formal test. Some just want to become familiar with the way Ralphs amp sounds. Thier opinion will be just that, their opinion. It is noteworthy that you never inquired of Ralph if any of his tests were blind.

If someone wants to develop a true blind test protocol (Not an ABX challenge), have at it.
Unlike Ron I am not prejudiced. I do have a smidge of class D exposure. I do however have some tube bias (pun intended). I have been on record as not liking class D.
I have warmed up significantly to the Merrill amps. I think they hold a lot of promise. I do not see them as Ralp does (tube killers). I still regard them as at best, a lateral move. I have no idea what the future holds.

 

[the sound of Tao]

Unless the comparison is blind perceptual bias/prejudice will likely color the result (either way, pro or con class D).

These amps won’t replace all tube amps in a 10 year period if they can’t ultimately overcome listening bias… they are either clearly subjectively preferable to tube amps or they aren’t.

We can’t divorce experience from the phenomenology of experience. That is to say we build expectation and we have retention of experience and we constantly sharp change between these states and that then our consciousness is ultimately modified and reshaped by these experiential shifts.

All amps face these exact same challenges and potentials of needing to reframe experience if they want to shape retention and build new expectation. But to fully meet the claim that they are tube beaters they will have to convince people the shift is actually clearly beneficial. The four audiophiles I suggested are all examples of people who have a range of valid experiences and show they can clearly articulate their experiences… that is all that can really be expected and is what is needed to start to build a broader and more diverse balance of views and data points on the actual listening reality of Ralph’s new class d amps.

 

[Gregadd]

This has been a painful issue of this thread where much much more than usual there has been the claims and repeated insistence that only already fully signed on new Class D acolytes can be the only ones who know the truth in how these Class d amps are demonstrably better than all tube amps and all the rest of us according to some are apparently fools for not believing and just following suit in processing ourselves into new class d converts.

Perhaps it would be good for Ralph to set up a new year put up or clam up all round Class D is new best amp type challenge.

The amps are very light and manageable. Ralph could reasonably and I’d imagine affordably send a fully burnt in pair to do the rounds at perhaps PeterA, Tima, Ron and MikeL’s for proper objective forum respected home evaluation.

This would be a great marketing opportunity for Ralph given his absolute faith in the inherent superiority of his new amps. The claim these new class d amps are better sounding, more transparent and more musical than any existent tube amp would make them more than fair comparison competition for Peter’s Lamm SET based horn system, Tima and his Atmasphere experience and Lamm gear and previous AR amps and Mike’s sota SS amps and Ron’s top end trad VTL push pull tubes. All four of these well established members have had very real exposure to the sorts of tube amps that this thread claims should be simply not as good or even as musically engaging as Ralph’s Atmasphere new class d amps. Why not simply put this to the test. If these amps are indeed good enough to put all tube amps out of the market within a decade this would be a good and transparent way to allow them to show their stuff and open the conversation up properly. If all the players were willing sign on I am sure Ralph’s amps would get a genuine fair hearing.

Certainly, those who rely heavily on measurements would not suggest you can't have an opinion, if you have not heard the amp. That is the substance of their argument. That is if you don't hear what measurements predict, it is you who are flawed versus the limitations of their measurements.

 

[JSA]

These amps won’t replace all tube amps in a 10 year period if they can’t ultimately overcome listening bias… they are either clearly subjectively preferable to tube amps or they aren’t.

We can’t divorce experience from the phenomenology of experience. That is to say we build expectation and we have retention of experience and we constantly sharp change between these states and that then our consciousness is ultimately modified and reshaped by these experiential shifts.

All amps face these exact same challenges and potentials of needing to reframe experience if they want to shape retention and build new expectation. But to fully meet the claim that they are tube beaters they will have to convince people the shift is actually clearly beneficial. The four audiophiles I suggested are all examples of people who have a range of valid experiences and show they can clearly articulate their experiences… that is all that can really be expected and is what is needed to start to build a broader and more diverse balance of views and data points on the actual listening reality of Ralph’s new class d amps.

I was one of those that decided to stay with tubes (Wavac monos) as for me Atmasphere Class D was too lean sounding...
In this thread alone, opinions are quite split among those that had a chance to try Ralph's class D monos.
If indeed burn-in makes such a significant difference, I find it strange that units are shipped without factory burn-in...

 

[PYP]

I'm assuming that @Atmasphere is making a point about how pervasive audiophile Class D can become based in part on the lower cost of manufacturing and the light weight (shipping worldwide for much less than heavy amplifiers), both of which open the field to competition and innovation.

And Class D is a good option for all-in-one/integrated setups, which seems to be a growing market. If that means that Class D can help expand the overall audiophile market, especially among younger folks who typically don't have a lot of space (as well as providing a good option to older audiophiles who are downsizing), that is something to applaud.

 

[DonH50]

Several decades ago, starting into the audio world, I "knew" what I heard and was certain I could distinguish differences among many things. Furthermore I had a reputation for it and was called in to help during listening tests of new (and old) equipment. Then I undertook a series of various flavors of blind tests during the early 1980's that were a revelation. Most of the things I thought I heard went away in blind testing, some things appeared, and overall it was a very humbling experience. I actually had some discussions with one of my psychology professors (I was pre-med back then) about the whole perception bias thing and how hard it was to prevent, even subconsciously. I was convinced I had no predisposition in some tests and found out I was wrong. I also learned that it is very difficult to run a proper test, whether of audio components, or a (paper) survey about whatever.

Blind testing generally looks for differences, not whether one is better or worse, so in this case whether a tube amp and a SS amp can be distinguished. I have never found that particularly difficult for amps driving speakers, though it depends upon the speakers and so forth. Preamps were tougher.

Enough diversion, I need to bail before I get in more trouble and get asked to leave again. I think listening tests would be great, but very hard to draw conclusions from. That said, I officially put in my offer to participate. Ralph, send me a pair pf MA1's and your new class D amps, and I'll listen to them for a while, and publish my results. Should probably spend a few years with them just to be fair.

 

[Gregadd]

To go even further I was told a blind testing is only necessary for small differences.

I think it is not enough to listen. We need to have at least at rudimentary understanding of why something sounds the way it does. We can make intelligent decisions in minx and matching equipment.
I know for blind testing is a hot button issue. From an audiophile perspective it is rarely done correctly. And the results are often subject to a proper statistical analysis. I don't want to turn this thread into a debate on blind testing.
I am sorry if I offended anyone. No one has to leave this thread.

 

[Holmz]

I was one of those that decided to stay with tubes (Wavac monos) as for me Atmasphere Class D was too lean sounding...
…. <omitted>…

^Exactly what I was trying to describe^ with the “quietness” of sound when the distortion is low.
with “lean” being opposite of meaty - I suppose.

Maybe having the distortion jump during the louder sections gives other amps some extra dynamic Zing.

However I do find that when the system sounds quieter, then I tend to prefer that.
Many others do not, and prefer the opposite end with more meat... and harmonics that spice up the underlying signal.

 

[BruceD]

Interesting thread--If anyone had said to me who is going down the Class D road in 2021-- I'd be in last place with a vote for Ralph !

With flak flying faster than a LBGT meeting--I must commend R for his patience with his replies showing a commendable perseverance.-kudos!

On the Class D Amps--I bought the Infinity SWAMP Class D Amp from Arnie N' in 78--it was not particularly world changing --adequate performance
unfortunately it died after only under a years light use --the little black Box module inside --its "heart"? gave up and Infinity had no more.

$$'s down the gurgler

Tao is correct about user bias, in my case I swore not to venture the category again.

Then again maybe Ralph is onto something ?

BruceD

 

[DonH50]

I thought the Infinity amp was the least reliable amp around, until I got an original Blaze Linear 700...

 

[Kingrex]

My substantive point is I love audio equipment too. without music it would be merely expensive "boat anchors." IMO YMMV

A good boat anchor is not inexpensive.

 

[analogsa]

Not sure why class D amps are compared to tube amps. Wouldn't comparing them to similarly specced SS amps be far more sensible? Tubes do certain things better than non-switching solid state and vice versa, there simply cannot be a universal winner.

 

[Gregadd]

A good boat anchor is not inexpensive.

Who said they would make good boat anchors?

Not sure why class D amps are compared to tube amps. Wouldn't comparing them to similarly specced SS amps be far more sensible? Tubes do certain things better than non-switching solid state and vice versa, there simply cannot be a universal winner.

The designer said they are as good or better than his own tube designs. That makes for a great discussion don't you think?

 

[BruceD]

I thought the Infinity amp was the least reliable amp around, until I got an original Blaze Linear 700...

Ha!-Yes well the crafty Arnie bribed me with a hair raising scoot around the Valley in his Black Porsche Turbo!

Sucker I was---at least I lived to tell the tale!

BruceD

 

[analogsa]

The designer said they are as good or better than his own tube designs. That makes for a great discussion don't you think?

It seemed it was a general discussion of Atmashere's class D vs Tubes, not vs the tiny tube amp segment called OTLs.

Comparing Atmashere's OTLs to their own class D does indeed make sense. Now that i think about it, OTLs and class D are similar in many ways, even audibly.

My objection was towards including DHT SETs or transformer coupled PP amps to the comparison.

 

[Ron Resnick]

The designer said they are as good or better than his own tube designs. That makes for a great discussion don't you think?

+1
fascinating, yes