Atma-Sphere S-30 MK3

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: http://www.audiogon.com/cgi-bin/fr.pl?aamps&1217516876

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.

Best,
Tom

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...

Emaillists,
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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.

AudioFeil,
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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..

Tom,
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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..:)

Best
AG