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..!

TIA

AudioGrails
128x128audiograils
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 http://www.atma-sphere.com/papers/paradigm_paper2.html
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....
Ralph,
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.

AG