[roscoeiii]

Andy-c,

Let's not put down the perspectives of others please. You are newer to AC, but one of the things I like here is the sense of audio community. Comments like "brazen BS artist", "complete nonsense" "utterly incompetent and unlikely to have the ability to design a decent amp to begin with.  So I think this is conscious BS artistry and not an attempt to describe legitimate engineering" are unnecessary, and contribute little to the discussion or the community here.

The author is Ralph Karten of Atma-Sphere. I rank him in the top ranks of amp designers. Right up there with Nelson Pass, John Curl, Bruno at Hypex and other great amp geniuses.  He is the preminent builder of OTL tube amps at the present.

Have you ever heard an Atma-sphere amp? They are sublime. Maybe not to everyone's tastes, but what amp is? And his amps, like any amp, need to be paired with an appropriate speaker. But with the right speaker and if it was in my budget, I would buy another Atma-sphere amp in a second. Check the reviews if you aren't able to hear an Atma-sphere yourself.

And really, the article is describing paradigms being used. Each of which is suited to different types of speakers, and each of which may have different design goals. And it is conceptually useful to think about the different paradigms being used by different amp (or speaker or turntable or any component) manufacturers.

[roscoeiii]

The other thing that Ralph from Atma-sphere also often raises is the importance of paying attention to psycho-acoustics. Let's not forget the unique ways that the human brain processes audio inputs.

[medium jim]

It is an amazing link, but not for the reasons you might think.  I'd like to cut the writer some slack and refer to him as merely a brazen BS artist.  Anybody who knows anything at all about amplifier design will immediately recognize what's written there as complete nonsense.  I wonder if the writer actually believes his own BS, because if he does, he is utterly incompetent and unlikely to have the ability to design a decent amp to begin with.  So I think this is conscious BS artistry and not an attempt to describe legitimate engineering.

Unfortunately, this situation has become the norm in the so-called "high end" of audio.  Many of the people designing this stuff don't have a clue WTF they're doing, but they really know how to do the marketing thing.  It's sad, really, because so many people not only fall for it, but actually think that people who do not fall for it are in the wrong.

Andy, I think you actually believe what you wrote, sad.   In corroboration of the link you call pure BS and wherein you slander the author:

http://lenardaudio.com/education/14_valve_amps_7.html

Jim

[Davey]

It's just a lot of flowery sales talk to differentiate low output impedance amplifiers ("voltage paradigm") from very high output impedance amplifiers ("power paradigm") like the Atma-Sphere designs.
There's no useful information at all on that webpage that would help to answer the basic query of this thread.

The type of amplifier advocated/built by Atma-Sphere will cause large frequency response swings in speakers with varying impedance loads relative to those with low output impedance amps.
Whether these FR swings are a subjective improvement or not is beside the point.....it's an objective cause and effect relationship that is easily understood/measured.  And it has nothing to do with the horrible negative feedback in the "voltage paradigm." 

Cheers,

Dave.

[roscoeiii]

Davey,

Ralph at Atma-sphere will be the first to admit that his amps aren't well suited to all speakers. Like I asked andy-c, have you ever heard an Atma-sphere amp into speakers that they are well suited to? They sound superb.

Into speakers that are a good match, I have also heard the following other amp designs sound superb: ncores, Class A solid state, hybrid tube-SS designs, SETs, push-pull tubes.

Any paradigm offers a unique way of thinking which then entails certain consequences as a result.

And for those without a technical background, this is a nice shorthand for characteristics to consider when evaluating amps and the speakers that they may or may not pair well with.

All that said, yes bringing this up is going a bit OT, but amp-speaker pairing is so important that I couldn't resist bringing it up.

[Davey]

No, I've never heard (or even seen) an Atma-Sphere amplifier.....and have no desire to.  That type of product is not what I think "high-end" audio should be about. 

However, if you supplied me the impedance profile of a speaker and identified which Atma-Sphere amplifier was being used, I could probably supply you a pretty good SPL diagram showing how much the response of the speaker would be skewed.

DS-21 has posted a nice example of how response is skewed with an amplifier which has a 2 ohm output impedance.  Looking at the spec's of some of the Atma-Sphere amps, I see some that exhibit even higher output impedances.

Obviously, there are certain speakers that might be more well-suited to that type of amplifier, but the majority aren't. 

Regardless, this type of discussion has little to do with the thread topic.  I'm not sure why you brought it up.

Cheers,

Dave.

[roscoeiii]

Dude, calm down. And I'd encourage you to hear as many types of amps (and speakers, etc) as possible.

I get tired of absolutism in audio from people who have not even heard what they are talking about.

There are many flavors of high-end, and I don't think many folks or maybe anyone who has heard them would argue that Atma-sphere amps wouldn't qualify as a compelling example of one flavor of high end.

From one review (emphasis added): "These are world-class amps that deserve your attention." From another: "What the MA-1 Mk II.2 does, no other amp I've heard so far duplicates." Another: "I knew the bar of expectation for lifelike sound had been raised. Going forward, there was no way my ears would accept less." " I have to choose just one -- the amp that will be the conduit through which all of my music, digital and analog, passes. Which will it be? Solid-state or tubes? Push-pull or single ended? Give me OTL in the form of the MA-2 Mk 3.1s and I'll live musically ever after." One more: "I've heard many very good amps and a few that are great; as I type this, I'm convinced that the MA-2 Mk II.3s are the best of them all." And from Harry Pearson: " Its ability to encompass quite wide dynamics while resolving , during forte and stronger passages, the quieter and more nuanced small dynamics from other instruments, is unsurpassed in my experience. Combine the dynamics and the clarity and accuracy of its reproduction of fast (and slow) transients, and you reach what I believe to be a new level of realism in home playback...Something quite special is at play with this amplifier and part of the enchantments it weaves seem, given the similar strengths exhibited by the Joule, a function of OTL technology."

OK, I am done with this diversion.

[jtwrace]

have you ever heard an Atma-sphere amp into speakers that they are well suited to? They sound superb.

I had M-60 MKIII on 95db speakers and they were far from superb.  Three other members on this forum found the same thing.  Sonically one must enjoy that odd sound from them.

Just sayin'.

[S Clark]

No, I've never heard (or even seen) an Atma-Sphere amplifier.....and have no desire to.  That type of product is not what I think "high-end" audio should be about. 

Fortunately, there are many members here who have had more experience with amps than you. You might pm Big Red Machine, who has probably run more amps through his system than all the posters on this thread combined, and ask him his opinion (based on actual listening experience)- he bought an Atma-Sphere amp a year or two ago, but I think has moved on to something else.
When I bought my Moscode, I had already contacted those who had actually had one in their systems, heavily weighing those who had paired it with the same speakers that I own.  There is a wealth of knowledge here at AC- for those that don't already know everything.
Scott

[Davey]

Dude, calm down. And I'd encourage you to hear as many types of amps (and speakers, etc) as possible.

I get tired of absolutism in audio from people who have not even heard what they are talking about.

Who's not calm?

Dude, $14,000 amplifiers are not on my radar screen, sorry. 
I moved past being interested in big-dollar audio equipment about 25-30 years ago.  (I spent too much money on gear.)  Now I'm interested in value.

I get tired of people in audio that reject discussion/opinions from folks simply because they haven't experienced something firsthand.

Cheers,

Dave.

[roscoeiii]

I had M-60 MKIII on 95db speakers and they were far from superb.  Three other members on this forum found the same thing.  Sonically one must enjoy that odd sound from them.

Just sayin'.

Glad that you have heard them. Hearing and preferring something else (or thinking their sound odd) is one thing. Dismissing them without having heard them is another. What were the speakers?

I clearly really liked the sound of the S-30 I had on my 96dB efficient speakers at the time (DIYs with Audio Nirvana drivers and on high 16 ohm impedance Zu Soul Superflys). Wouldn't call it odd, but the words fast and clean jump to mind.

[jtwrace]

What were the speakers?

GedLee Abbeys

Wouldn't call it odd, but the words fast and clean jump to mind.

OK..

[roscoeiii]

I get tired of people in audio that reject discussion/opinions from folks simply because they haven't experienced something firsthand.

Cheers,

Dave.

I am not rejecting your opinion Dave. And you are raising important technical points about these amps. However two things stand out in my mind (and please don't read this as being confrontational. I don't mean it in that way.):

1) How should opinions of those who haven't experienced something first hand be regarded in your opinion?

2) To have no desire to hear an amp that has received such high praise seems odd.

[jtwrace]

I am not rejecting your opinion Dave. And you are raising important technical points about these amps. However two things stand out in my mind (and please don't read this as being confrontational. I don't mean it in that way.):

1) How should opinions of those who haven't experienced something first hand be regarded in your opinion?

2) To have no desire to hear an amp that has received such high praise seems odd.

If ones opinion is based on science then it's easy.

[Quiet Earth]

Dumbest thread ever.   

[roscoeiii]

If ones opinion is based on science then it's easy.

But let's be sure to remember that a) there is much that science still doesn't understand b) that there are limitations to measurements (to focus only on what can be measured means that certain aspects of experience are going to be excluded).

This applies across the board, well beyond the audio world.

Not that measurements aren't important and helpful.

But in the audio world, we shouldn't get too caught up with them at the expense of direct experience.

[roscoeiii]

Dumbest thread ever.   

Oh I am sure there are dumber ones out there...But yeah, I apologize if my comments have led this thread off track.

[medium jim]

If ones opinion is based on science then it's easy.

Interesting comment, the science is against switching amps..., wait, there is flaws in every topology, speaker design that exists today.  It truly does become a matter of personal preference.  That said, I agree with Roscoe that the absolutism serves no redeeming purpose.  The "my shit is better than yours" sure gets old.

Jim

[Freo-1]

Antony Michaelson of Musical Fidelity had this to say (large missing segments indicated by "....."  and italics his):

"Dear Fellow Music Lover,
Many customers ask me about the design aims of my products. They are particularly puzzled by how Musical Fidelity can strongly
promote the merits of high powered amplifiers such as the 550K or 750K whilst on the other hand producing low powered amplifiers such
as the A1. I’d like to try and explain my ideas.
.....
Accuracy and realism.
I strongly believe that with an ordinary high quality loudspeaker of about 87dB sensitivity you’ll need about 500 watts to avoid any
clipping or limitation. I cannot stress strongly enough that this assumes that you are using the system at a healthy, quite loud, listening level.
If you listen quietly or are in a small room or sit close to the loudspeakers, the high power figure is irrelevant. My point is that if you want
accuracy and realism the amplifier should never clip or limit.
.....
Keith Howard is an experienced technical journalist. His research has confirmed that 500 watts power is a good level for a properly neutral
system. He also suggests that if you really want no clipping, that you would need even more power. His position certainly appears to agree
with ours but there is more to his research. After finding out how much power he thought the system should have, he then set out to find
out how much clipping would be subjectively acceptable without much apparent loss of neutrality.
After a lengthy experiment, Keith found that about 3dB of clipping did not cause much upset. This equates to 250 watts.
To summarise the above: if you want to be sure of almost complete accuracy and neutrality you need an amplifier of 500 wpc (or more) but
250 wpc will be acceptable for most people most of the time. A little inaccuracy never did anybody any harm.
.....
Once you are below 100 watts clipping (with my previous points taken into account) is a regular feature. It follows that the dynamic
reproduction is no longer neutral, accurate or low distortion. Once you’ve reached this area subjectivity becomes far more relevant. Each
amplifier has a unique clipping/limiting characteristic.
.....
Once you’re down to below 100 watts amplifiers will be clipping regularly. At this point reproduction is inaccurate. Now the amplifier
design is rather like an impressionist picture. It cannot be a photographically accurate representation of the recording but somehow has to
create the impression of the musical performance. At this level the limitations of the amplifier have to be accepted as a constant and the
design has to be created in order to give the most convincing illusion of musical accuracy.
.....
Now to the A1. Yes it doesn’t have much power and yes it’s clipping regularly (but not much more than any other amplifier below 70 or
100 watts) but we have accepted its power limitations and have decided to engineer it to produce a convincing, beautiful, musical
experience.
When I listen to the A1, I am completely blown away by it. It has an apparently sweet, subtle, delicate sound which seems to make
something of a nonsense of my high powered ideals.
However, as soon as a you switch to an amplifier which has enough power not to be clipping, it is immediately obvious what you have
been missing. The point is that whilst listening to the A1, its ability to project and create musical illusion is so strong that I don’t object to
its power limitations. In my world, that’s job done.
.....
Over the years I have had endless frustrating run-ins with reviewers and hi-fi salesmen about the accuracy of what they’re hearing. When I
have taken them a proper, high powered amplifier to use, their immediate reaction was that it was “dull” or “undynamic”. What they were
hearing was completely faithful and accurate but what they wanted (or perhaps expected) was the usual clipping and limitation. Very, very,
very frustrating."

Excuse the length of this post, but I thought some would benefit from the clarity of this, from an honest designer. I post this because it seems not to be on MF's website any more.

 
This is good information.  Thanks for posting, as this gets to the heart of the wattage matter.
 
 
 

[neekomax]

Dumbest thread ever.   

I don't find this thread dumb at all.

And I also think that there's nothing wrong with expressing strong opinions either way. A lot of times when these AC threads veer into controversial territory (obj vs. subj, etc.), there's this immediate reflex I've noticed to quash strong opinions, as though people's feelings were on the line or something. Dude, it's audio. If someone feels strongly about a certain topic, I want to hear about it. Obviously, the line should be drawn at personal attacks, but I almost never see those here, honestly. And saying 'the approach you prefer isn't good because x' IS NOt a personal attack. No one's saying you're a bad person, or your mama dresses you funny, or that you're an a-hole. The worst that can happen is that someone might consider a different opinion than their own for a minute, and possibly feel bad about having spent mucho cheddar on gear that someone else thinks sucks. So what? From what I can tell, most of us are at least middle aged, shouldn't we be comfortable enough in our own skin by now to have even a heated discussion about this stuff without having to hold hands and sing kumbaya at every moment? I too love AC for the suppotive community vibe, but I also know that I learn the most when reading a discussion that contains more than one viewpoint.

In other words, please don't IWB this thread just 'cause it's interesting, and we're not simply congratulating each other for being such awesome audiophiles.

/endrant

PS - I love you all