Atma-Sphere MA-1 amps


How good are these amps? I have 200w Class A mono blocks and have been eyeing these for sometime. What are your thought on them and hwo do they sound?

TIA
128x128jtwrace
Hello Jtwrace,

Please remember what I'm about to tell you in my post is just my opinion and nothing more. It doesn't mean it's true to anyone else besides me, but it is honest, sincere, and the way I hear it. I was waiting to post hoping that someone else would mention what I hear so I wouldn't be the first to have a negative comment about these extraordinary amps. From the many positive comments of all the people who have posted I don't think at this point that is going to happen. Another caveat to consider from my post is that I most definitely have a hearing impairment from 35 years or so of working as a musician. My comments are made with all due respect to my friends who have posted to this thread and to Ralph.

I myself came extremely close to a purchase of Atma-Sphere MA-2 amps to feed my Avalon Eidolon Diamonds. I was privileged and fortunate enough to hear these amps 5 different times at length, once on the standard Eidolon which were my previous speakers, and four separate times on the Diamonds. I was assured that the amps were totally broken-in so I feel it is reasonable to rule out that as a factor and also because the problem for me was exactly the same to various degrees each and every time I heard them. For me, what they did so very very well almost caused me to buy a pair of MA-2's. This is why I feel it is important to post opinion. It was only until the last two times of hearing the Atma that I decided I wouldn't be able to get past the problem I was having, and in the long run the problem would become fatiguing for me.

First the positive .... this is actually an understatement. In this specific way the Atma-Sphere MA-2 ( latest and greatest version ) rendered the most realistic sense of transparency I've ever heard from an amp .... period! The openness and air of the sound-stage the detail, simply magic. WOW!!! The only other OTL amp I heard before the Atma was the Tenor 75 watter. The Tenor had this same quality but not to the same degree. The sound-space wasn't quite as open and airy, however texture density I felt was a little more truthful. Textures were IMO more full bodied and harmonically complex with the Tenor OTL.

OK, here it goes ............. the flaw I felt I just wouldn't be able to get past was the longer and more times I listened to these amps I became increasingly aware of an unnatural band of frequencies in the treble. Certain notes in the upper registers on piano, vibes, and violins for instance had a bite, almost like an overshoot of attack, kind of like the amp was trying too hard to sound fast in the high end. I'm sorry to say that for me the more I listened the more I was made aware of the fact I would not be able to get past this character in the long haul. I heard a parallel to the Martin Logan CLS 2Z speakers I used to own. Some of you may know first hand or read this about the CLS, in certain ways they were undeniably more transparent than other speakers, so transparent in fact the images were a little ghost like needing a little more IMO texture density to sound real. But the big problem was, because of the taxing load it put on amps paired with it, the upper frequencies had a glare and bite to it that on certain notes would be like looking directly into sun.

Again, my post is just my take. It is not meant in anyway to be disrespectful to the other poster's opinions giving here and I can certainly hear and understand why many people would choose the Atma-Sphere amps, the strengths they posses are so compelling. This is a sizable investment and I felt my opinion may be of help. I wish you all the luck in finding the right amp for you

Best,

Tom
I was wondering if Ralph ever visits this forum....if he does, does he usually comment about his products?
Hi Tom, good to see your post! One thing folks should be aware of about the A-S amps is that the choice of 6SN7 driver tubes will make a big difference in the sound. In the MA-2s you heard at my house on the standard Eidolon, Tom, we were listening to Sylvania 6SN7-GTA tubes manufactured in the '60s. These have a very clean, detailed and somewhat airy top end. Put in something like RCA grey glass and the top will get much softer and sweeter. Do you know what 6SN7 tubes were being used in the MA-2s you listened to on the Diamonds?

Warm regards my friend,
Hello Rush,

I'm afraid I don't know the brand of the 6sn7 tubes that were in the other 2 pairs of MA-2 amps that I heard. I imagine it was the stock 6sn7 that were supplied with the amps from the factory.

Rush, I heard far less of this treble abbreviation in your system then the other two systems I heard with the Atma/Diamond combo. This is before you had your amps brought up to to the latest version. If I'm correct, the latest upgrade included the new caps. I have a sneaking suspicion that the new caps are responsible for the sound I'm trying to describe. To me it's ironic that I think the caps are also what gives the sound this tremendous sense of openness. It would be interesting to hear from others if they feel the flaw I can't seem to get past is innate to the new caps.

Rush, I also remember you and Ann having issues when you first made the upgrade. Do you feel these issues have completely dissipated over time with break-in? Or is there still some remnants of those reservations remaining? Thanks so much for your candor. Maybe a learning experience can come from this discussion.

As always - your friend,
Tom
Rushton's comments on the driver tubes are right on. I found a combination of RCA GT Grey glass with Sylvania GTBs to be just right, the RCA are a bit more "romantic" sounding than the Sylvania and just right in combination for my ears. Same thing in the preamp, where tube rolling changes the sound a bit from neutral to warmer - in general RCA (warm) Sylvania more neutral. I'm not sure that tube rolling would address what Tom hears, but it might.