Atma-Sphere S-30 MK3

To Atma owners and gurus;

I've just recently jumped on the Atma wagon and I must say that so far this has been the single most eye & ear opening amplifier experience in my entire audio life of almost 28 years.

The S-30mk3 has been residing in my rig for close to 4 months now and is still breaking in, but should be almost done anytime soon.

I do however complain of an un-natural tonality in general that comes and goes during the break-in period and which was also very clear from the beginning. This is also accompanied by a certain 'hardness'..much like looking directly into sunlight as opposed to looking through a pair of poloroids..This issue is really bugging me and was wondering if it's part of the break-in process of Atmasphere amps in general, as I have never experienced it with other amps, tube or SS..

This aside, the amp seems to be taking forever to break-in..!!! But, it certainly looks to be my holy grail in amplification.

Along the way, I replaced the stock Chinese 6SN7's with EH's and now settled on Tung-Sol's. The latter being the best sounding of the lot. I do wanna stick to current production tubes as much as possible. Don't wanna go on the NOS merry-go-round..:-)

The S-30 is driving a pair of Tannoy Edinburgh's, from the Tannoy Prestige Series, to wonderful effect and the sound is heavenly! Preamp is a BAT VK-3iX Special Edition and is also a very good sonic match with the S-30..

Appreciate any input and of course any advice from the Atmasphere gurus and lovers here..!


This year I took possession of new MA1 MKIII's (having lived with the original MA-1's for 17 years)

I did not notice much of a break in. The difference from the (very) old to the new was evident immediately.

I also didn't notice hot and cold listening sessions, if I'm understanding you correctly.

The one thought that comes to mind is that perhaps the S-30 is slightly underpowered for your setup, which could account for the "hardness" you mentioned.

I see the Tannoy is 94db so they are pretty efficient (and 8 ohms, which is good for OTL's), however Tannoy rates 50-300 watts as the range? I'm just guessing here - maybe you are not driving the amps hard at all?

Also I suggest getting premium fuses (I use Hi FI Tuning).
Over the past 4 years I've had new S-30, M-60, and MA-1 amps here and experienced very little, if any, changes from the first time they were fired up to months later.

I suggest your ears were acclimating to the sonics and different presentation of an OTL amplifier.

Dealer disclaimer
Hello Audiograils,

Whew! I was beginning to think I was the only one out there who heard the same thing as you concerning the Atma-Sphere amps. My experience was in particular with the latest generation A-S MA2 amps.

Yes, I also found the treble attack as having a unnatural glare or bite. I also felt that texture of tone overall was lacking density and body, I heard it as being on the thin side of what I perceive as natural or neutral. In the thread I also used similar words " like looking directly into the sun" to describe this unnatural hardness in the treble.

If you haven't already, may I suggest that you read the thread because I was alone in my opinion. The thread is entitled "Atma-Sphere MA-1 amps".
the link:

I hope it turns out to be just a burn-in issue for you as I know in my experience I find certain aspects of performance of the A-S amps to be .... truly one of a kind.

My Atma "resume": I'd used M-60s for a few years and upgraded to MA-1s almost a year ago.

Does the "hardness" occur at at both modest and loud volumes? Has it "been there" and "not" on the same recordings, but during different listening sessions?

Bill's comment about an OTL amps's "different presentation" likely gets to the heart of the matter, especially as this hardness manifests inconsistently. Atma-Sphere amps don't run with the herd. Transparency/accurate tonality and clarity are their strong suit, yet no amp is perfect in all qualities.

I've no experience with the M30, but compatible loudspeaker matching likely is more challenging given the lower power, as Emailists suggests. The overall "flatness" of your loudspeakers' impedance curve can also influence sonics when using OTLs. The power factor may manifest at higher volumes or with uncompressed and very dynamic recordings. The effect of unfavorable loudspeaker impedance peaks may be more evident on some recordings than others, as it would be frequency-related. But this is just my very speculative 2 cents...

Thanks for your input. The Tannoys are matching very well power wise. The version I have is the TW which has a 95db efficiency, an RMS rating of 110 Watts and a Peak power rating of 380 watts. Changing fuses is under consideration soon as I get a consistent performance.


Like any other audio gear, the Atmasphere changes sonically during the break-in process but it takes quite a long while between these changes. I ordered it with the Teflon Cap upgrade, maybe that explains the unusual long break-in time..


This indeed is a coincidence!..I posted on Agon as I found more user discussions here on Atmasphere than anywhere else..:) I ordered the S-30 with the Teflon Cap upgrade, so maybe the Caps are the culprits till break-in is over. Maybe the MA units you heard also had these Caps installed. Maybe there weren't fully broken-in. I'm just guessing of course.

Recently, I also tried different interconnects and power cords but still this hardness existed. Mind you, it has greatly subsided but it is still there and noticeable and of course annoying..:) I brought over a couple of audio buddies and they too confirmed the phenomenon. Mostly very noticeable in a piano's mid to upper registers and the trebles in general.

This anomaly was also the reason why I experiemented with other 6SN7's but still no change, though the Tung-Sols were superior (to my ears).

Tom, thanks for the link. I'll check the thread and read the opinions there. I'm really hoping matters take a good turn soon as I really love this amp and love the way it reproduces the music. Thanks again for chiming in..:)

Nice amp you got there. There's one in my living room, too.

I haven't experienced what you describe during break-in, so can't make any suggestions on that topic.

However, I do have some experience in designing speakers to work well with the S-30 (as well as with other amps, but the S-30 drove the design). In my experience the speaker's impedance curve is a very significant factor.

I don't know what the impedance curve on the Tannoy Edinburghs looks like, but if it has a significant peak or two in the upper midrange or treble region the S-30 would put out increased power into that peak, especially relative to what a solid state amp would put out. And increased energy in the upper midrange and treble region can come across as "hardness".


Thank you for helping me understand Atma-Sphere products and break in Audiograils.

Your experience is most helpful.

I had no intentions to sound nasty or inappropriate !! I was merely saying that I noticed vast sonic changes during the break-in process of the amp in contrast to what you remarked.

" I suggest your ears were acclimating to the sonics and different presentation of an OTL amplifier. "

>>I couldn't agree more on this<<

Thanks for your input and my sincere apologies for the misunderstanding.

Duke's speculation makes perfect sense as a possible explanation. I use M-60 MKIIIs with my Merlins that have very flat impedance with no frequency anomalies that I can detect. Now, I have heard that V-Caps do take a while to break in, but I'm not sure that it would account for what you are hearing. I'm sure Bill has heard every Atma permutation so I assume he has not picked up on this V-Cap breakin as being a possible cause for your situtation. Let us know if thinks improve.
I have the S30 mk3 OTL amp with the upgrade vcap and resistors. The break-in period for me lasted only a couple of days. I loaned the amp from a dealer and for the first day it really didn't gel and I was very close to handing it back.

However, day 2 was different and I started to really appreciate how revealing this amp is. I am using it with a Bent Audio TVC and Avantgarde Duo Omega horns which have a flat impedance of 18 ohms.

The imaging and dynamics of this amp are second to none in my system and I do not hear the hardness that you are referring to. In fact I would say that it is amazing how high you can set the listening level without and strain or hardness appearing.

I am using the amp in balanced mode with Anti-IC's and stock power cord.

Hope that helps in some way.
If I may to offer a differrent perspective.
This discussion sounds utterly familiar to one , that took place in the infamous "Preamp deal of the century" Supratek thread, regarding "glare", that some Supratek owners (myself included) heard in very different systems, that employed Supratek preamps. Our impressions were very similar, but at the same time an obvious minority. The vast majority of Supratek owners couldn't understand what glare we were talking about, and the general consensus in the end of that discussion was pretty much:" Majority of esteemed and experienced A-gon members didn't hear the glare, and the small number of owners, who did, obviously didn't know how music is suppose to sound".
Fast forward from my Supratek phase, and after having some other preamps in my system- Doshi Alaap, and now I have BAT Rex with BAT-75 SE (graciously lended by a friend), I can say with a high degree of certainty, that I just confirmed my impressions of Supratek as very colored, bright and definetely exibiting glare in the upper midrange (not at all dissimilar to "looking directly into sunlight).
To sum it up, my point is this- I think we all have different sensitivity to certain parts of the audible frequencies, especially upper midrange, treble.
It can be attributed to the age differencies for one, and to a multitude of other physiological factors as well.
BTW, I retrospectively think, that Supratek's "glare" is attributed to silver-plated copper internal wiring, used in the chassis (it's point-to point wired).
Now, I'm sure, many will conside my post rediculous, and will continue to defend their own listening experiences, as "the one and only truth", which in the context of one person's hearing abilities, is such.
IMO the product was un-natural in the top end,but thats listening at a couple dealer demo issue with the line is kind of like buying a get a product that needs alot of added stuff at the getgo..doesnt make sense to me to have to upgrade a tone to get something worthy
Based on your obvious unfamilarity with the line it's highly doubtful you could hear the difference between a stock unit and one that is highly optioned.

There's very little to learn in a dealer audition when the system contains none of your components, cables, and room acoustics.

I suggest your comments are those of an inexperienced listener.
Mission, I think the upgrade path is prefereable to having three models to choose from and having to sell my unit to move up the line. It seems more cost effective to be able to buy what you can afford today, and move up the chain as money allows. The product is more than "worthy" in basic form, but allows even better performance down the road - I think this approach makes a lot of sense as a owner/user.
I suppose I should clarify a few things, after some emails I got regarding this thread.

With regard to options: Being audiophiles ourselves, and inveterate tinkers, we know the temptation to look under the hood and see what can be hopped up. That's the sum total of why the option packages exist- we've tried all sorts of tweaks in the amps and preamps over the years and we include them if they have been shown to have merit, unless the tweak compromises reliability. So it comes down to the resistors and capacitors- we figured out which ones work, and those are the options. To date we've not found an example of someone using a different part that outperformed them.

All our products are built with a custom copper wire that is as pure as anything else out there- by rights, we could be cable company :)

With regards to the S-30: Two things need to be considered, actually with any of our amps:

first, they are very revealing (transparent). Please, before deciding that the amp/preamp is at fault (and especially if you use digital as your only source), try a different source! I find that poor digital electronics have glare artifacts to this day and is still one of the reasons I prefer analog. OTOH a good digital system can be listened to all day, but what is a good system and what will have glare is not all that predictable- certainly price has nothing to do with it... and often what others say about it or what your own experience has been with a less transparent amp/preamp could well be irrelevant. I don't mean to insult anyone, this is just my experience over the years (FWIW, overall the amps lack a reputation for glare amongst our customers- that phenomena is always symptomatic of one of these two issues I bringing up here).

Second: Duke and others are quite right: the amp/speaker interface is **crucial** (see
for why. Please note that the paper is not talking specifically about our products, although they do fall into one of the two categories discussed. The S-30 is one of the smaller OTLs made and runs very little feedback (a simple way to increase the feedback is to run the unit single ended, without the shorting jumper in the XLR connector; if the amp seems to sound better, then the impedance curve of the speaker is an issue- and can well be solved by use of a set of ZEROs.), consequently it is 'load sensitive' in the same way some of Nelson Pass' 'current source' amplifiers are. If the 'glare' is at a certain frequency (for example at the crossover), a simple Zobel network can be devised to correct the matter. The S-30 is a special case in that it makes more power at higher impedances, this causes some modern speaker crossovers to not work in the way that the speaker designer intended if they are used to Voltage Paradigm rules!
Transparency to the source is a two-edge sword. When it's good, it doesn't get better, but when it's not so good....
Very informative, as always.
When you said:
"All our products are built with a custom copper wire that is as pure as anything else out there- by rights, we could be cable company ",
I wonder, if you have found silver-plated copper wire to sound different (read glare), than pure copper. That has been my personal experience.
I don't what Ralph thinks, but Ken Stevens of CAT avoided silver for just that reason.
Thanks very much for your time and patience, very much appreciated. The 'glare', 'hardness', 'tonality issue'
were very prominant during the first 45 days or so but they slowly diminished along the way. Not much left now, only every other day or so and not so prominant as before. I'm almost positive it's a break-in issue somehow, as it's not a constant occurance and when it's there it's with any volume level. I was a bit worried it might be the speaker/amp interface somehow. The amp does take a long time than usual to sonically bloom and mature, it seems.

I also noticed that the all the tubes (6AS7) need to bias correctly as earlier on I had 1 or 2 that were running fine but not optimumly responding to the bias meter and gradually discovered that they contributed to some glare and hardness too. Once replaced, the sound was ok again.

Indeed, the Atmasphere 'sound' is totally unlike other tube amps, SE or PP, that I've experienced and , like Audiofeil mentionned above, needs some getting used to for a first time user. A very good 'sound' nonetheless..:-)

Ralph, as always, thanks very much for your patience and perseverance, your input in this thread and in private emails. If the S-30 is anything to go by, I wonder what the bigger brothers sound like !!! Great Job and God Bless.


In response to Atmasphere's post....

I just wanted to point out that I heard the A-S MA-2 amps with both analog and digital front ends, both of which are considered by the audiophile community to be at the very top of their game.

It was the same sonic fingerprint I heard to various degrees in all 3 systems (please refer to Atma-Sphere MA-1 thread) regardless of the source . I feel confident with my opinion that the sound was due to either the amp speaker interaction, or just my general take on the sound of the A-S amp.

"I suggest your ears were acclimating to the sonics and different presentation of an OTL amplifier."

If you believe this statement, which very well could be true, then you would have to conclude the A-S amps do have their own sonic signature.

Sincerely and with all due respect, on a public forum such as this, I feel that (IMHO) manufactures are better off sticking to posting only factual information about their equipment and refrain from posting any subjective opinions or comments as they will be biased.

"The S-30 is a special case in that it makes more power at higher impedances, this causes some modern speaker crossovers to not work in the way that the speaker designer intended if they are used to Voltage Paradigm rules!"

The 'Voltage Paradigm' should not be passed over lightly !
In an earlier thread titled "mo' better bass:any substitute for watts" this idea was investigated . While that particular thread was addressing bass , maybe Atmaspere could explain how it affects the upper end of the spectrum here .

I know that Atmasphere does not like the term 'synergy' but that probably is what is being discussed here . Some components work well together and some don't !
Tom, I think the dividing line between "factual" and subjective is might hard to draw - especially on the subject of how something sounds. I have no problem with a manufacturer saying whatever they want as long as their identity is clear; we can than apply as much salt as needed. For example, manufacturers tend to think their equipment will work in a broader array of system contexts than might be ideal for the "synergy" that Saki70 mentions. This seems to be the case with OTLs for example which with the right speakers are unbeatable IMHO, and with other speakers there would be better options.

I've read the thread you referred to in your first response. I'll be posting here again with my impresssions once the S-30 has been fully broken-in. So far it's on the right track. Still waiting for the 'body' to fully develop.


I've read the thread you referred to in your first response. I'll be posting here again with my impresssions once the S-30 has been fully broken-in. So far it's on the right track. Still waiting for the 'body' to fully develop.


NOS RCA GTA/Bs will add relative body and warmth should you find that breakin doesn't bring enough of it; though I'm not sure which of those driver tubes have the most impact on sound signature.
Maril555, we did run into some problems with silver-plated wire and it was both brightness *and* dullness! A lot seems to depend on the wire- its gauge, how its extruded, purity, the thickness of the silver plate, etc. We've heard some that are just fine (Purist made some wire for our use at one point). Copper is a lot easier- just make it pure and don't make the gauge too big :)

Saki70, the Voltage Paradigm showed up about the same time transistors did. I'm sure that's not coincidence!

In a crossover wherein the speaker designer uses series elements to cross over the driver, the actual crossover frequency can change a little if care is not taken to be sure that the upper and lower rolloff points in question do in fact crossover enough! IOW, you often need a dip in impedance at the crossover point in order to be sure that the crossover will be effective. This will cause a loss of power in the amplifier at about the same point that both drivers will be running, hopefully resulting in flat frequency response. Its a matter of taking care- the same scenario might not work so well with a transistor amp- the crossover point might have to be adjusted.
I just received my S-30 and noticed some thinness, hardness and brightness, as well, although the overall sound was stunning compared to my ss amp that preceded it. I changed my cabling from transport to DAC and the whole sonic picture changed immediately. The sound is now full and natural. There may be various causes for this complaint. One of the causes may be cabling.
Sabai, if your S-30 is brand new, what you are experiencing is the amp breaking-in. The sound will open up, get less harsh and have better bass as the electronic components settle in. Be patient, it only gets better.
Thanks for letting me know. I will wait patiently. Things are going so well so far with my S-30 that patience is very easy to come by -- especially since I changed some cabling. The S-30 is a real honey.
So Mr. Sabai we finally see/here eye to eye. A great amp you have there.
So Mr. Sabai we finally see/here eye to eye. A great amp you have there.