HP's
| W O R K S H O P |
The Year's Ears of Gold
Atma-Sphere MA-2 Mark II.2 Amplifier
Had I confined myself, in the field of basic amplification, to the best or most impressive, then the
Jadis JA-800 monoblocks would have gotten the nod. Or if I could have streached the definition of
year to the breaking point - and in giving these awards, we do use the term "year" loosely - then I
would have made a co-award for the Joule Electra Grand Marquis, the first output transformerless (OTL)
amplifier that deeply impressed me. The Joule was, in actuality, historically anteceded by Ralph
Karsten's Atma-Sphere OTL designs, one of which I heard some years ago. Without being unduly impressed.
The MA-2 Mark II.2 is something else. Karsten rates its output at 220 watts per channel - it's a monoblock
- into 4, 8, and 16 ohms, without telling us just how he managed this seemingly magical feat.*
An OTL amplifier should deliver its maximum output into one impedance with an attendant drop-off in power
at all other impedances. Indeed, that relationship between power output and the impedance curves has been
one of the bete noirres of OTL design, given the fact that the impedance curve of any given speaker
is hardly likely to be flat, whatever the "nominal" impedance of its particular design - Magneplanars,
of course, excepted. And some speakers, from, say, either Dave Wilson or Arnie Nudell typically have
quite sharp drops in impedance at some point in the lower frequencies, which could mean that an OTL would
run out of steam down yonder. We might consider the case of Nudell's triumphant comeback design, the
Genesis 350 Special Edition and the Joule - itself rated 160 watts or so into onto eight ohms - which
clipped its brains out when faced with the low notes from the The Thin Red Line. The Atma-Sphere,
on the newly arrived Special Edition, floated along, top to bottom, airily even as yrs. truly really
cranked it.
The MA-2 is, Karsten sez, "all triode" (push-pull of course), all class A, and with differential
operation from input to output, and zero global feedback at that! He further sez that it essentially
has but one stage of gain and switchable input impedance (600 ohms on the low side for those preamplifiers,
including Karsten's own that adhere to this "standard," and 200k/ohms on the high side when used with
other preamps in balanced mode, 100 k/ohms when used in single-ended mode, no doubt for Robert E. Greene's
delectation). And with a power bandwidth of 2 Hz to 75 kHz, a phase shift of less than a degree at 20 kHz,
with a stated frequency response of one Hertz to 200 kHz within a half a decibel, and it's only down 3 dB
at 1 MHz - measured at one watt, open loop. He also claims a slew rate - get this - of 600 volts per
microsecond. (It may or may not be a matter of significance that there are no distortion figures in the
basic specs.) As far as they go, these specs would do some Fancy Dan electronics proud and for a tube
unit, are, well, out there.
The first thing one notices, once these 130-pound, fanless, 26-tubed monoblocks are in place - other than
the ferocious amount of heart they throw - is their electrifying transient response. The same was true,
to be sure, with the Joule Electra designs, but here we find ourselves with the impression of both
effortless and unlimited power behind those transients, which can make the resulting sound quite easy on
the ear. Some of the "bright hotness" we attribute to , lets say, the Mercury sound disappears with this
amplifier. The transients are even faster and more refined in sound - the Classic redo of Mercury's
fabulous complete recording of The Firebird prove the perfect case in point. The "edge" goes off
the massed brass, but the brassiness of their sound remains. And there is so much backup power available
that, upon the entrance of the brass choir fortissimo, you can even hear the volume of air behind the
horns themselves, instead of an instrumental section that becomes less dimensional as the sound grows
louder. Coming from another direction, you can take the sound of a solo marimba, which can be massive
played forte , and hear its distinctive wooden timbres (not to mention something like its true size)
as it is struck hard. With normal amplifiers, including many a tube unit and virtually all solid-state
ones, a forte marimba glissando will sound not only somewhat metallic, but without its wonderful
decay pattern (the real mark of the marimba) and at anything but its massive size. With most amplifiers,
the harder you hit the marimba, the more two-dimensional, shrunken and metallic it will sound. (Source:
Lionel Ritchie's "All Night Long" single LP from Motown.)
Even strings, hardly classifiable as transient rich instruments usually, gain, at their best, the kind of
subtle sweetness and airy richness you get from a good ensemble in a good hall (again, note the sound of
the London Symphony strings on the Dorati Firebird). The downside of this, in some cases, is that
you can hear so deeply into a string section that sloppy ensemble work and slightly mistuned individual
instruments will be just easy to hear, but, worse, obvious. Push the MA-2 hard enough and it will
clip. (As it does on the new Genesis.) And that sound, which occurs high up in the spectrum, sounds like
a spritz on massed strings and brass. But as a practical matter, unless you're determined to burn out the
cilia in your inner ears, you aren't going to hear clipping.*
The MA-2 does have a characteristic coloration, one that is on the dark side. Not dark in the way of some
earlier Madrigal/Levinson designs, the result of too much feedback, which can attenuate high-frequency air
and bloom. But dark in the sense of a velvety background silence that doesn't seem to at all interfere with
top-octave bloom and extension. Jud Barber's Grand Marquis OTL design, it's worth noting by way of contrast,
does not have a "character" like this and is much closer to musically neutral (i.e., the way things are).
I cannot resolve this seeming contradiction in what I am saying just yet, because my work with Atma-Sphere
is yet a work in progress, like that with the Walker Proscenium Gold, and not near to my final
thoughts.**
Given the right material and the right speaker system (say the PipeDreams), the MA-2 can create an illusion
of real sounds that, at moments, are quite uncanny. 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. And even on digital recordings. Let's take, for example, the Finlandia recordings of
Sibelius' Seventh Symphony (with Berglund and the European Chamber Orchestra), as recorded by
Tony Faulkner at Watford in London. During the opening bars, there are sounds from the low strings and
woodwinds that really are close to facsimiles of what you'd hear in the hall, so "real" is their
depiction. I could hardly believe my ears. (See Scot Markwell's sidebar for a listing of equipment in
Room 1.)
There is also enough resolution for you to hear intonation errors in the viloins.
As happenstance would have it, I heard Loren Maazel lead the Vienna Philharmonic (at Carnegie Hall)
through the Suite Stravinsky excerpted from The Firebird, just after playing the Classic re-issue
of Dorati's reading. And for the first time, I found the recorded sound preferable to the live. I
never imagined that this could be so. (The Vienna evidently doesn't like Maazel, because they didn't
play well for him that night. As a conductor, I find him despicable because I don't hear the love of
music in his conducting - as say, with anything Bernstein did with the Vienna - but rather I sensed a
patronizing contempt for the audience as well as the music. I guess you had to see the snide way he
smiled when part of the crowd wend wild with the Firebird and an encore of the closing moments
of Ravel's Daphnis and Chloe that bordered on the vulgar and was actually louder that the climactic
moments of the Stravinsky.) This sonic realism from the PipeDreams did not materialize, by the way,
until finally we able to get and install Nearfields's spikes under the midrange/tweeter towers. At this
point, a kind of holographic - sorry I can't summon up a better word; others misuse it so - field became
apparent, with an intense focusing and specificity, much like what one feels sitting close to the orchestra.
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. Odd, don't you think, that
such a relatively antique technology could get us so close to the state of the art and the real thing.
The idea behind the Golden Ear awards is no to select what is necessarily the "best" component of the
year, but rather to let you know what our reviewers found most interesting, or intriguing, or downright
facinating in the course of their daily rounds. In other words, those components most likely to excite
your curiosity and interest.
*I wonder if the amplifier would begin to acquire that characteristic I called "authority",
something I've heard only from monolithic tubes amplifiers, e.g., The Audio Research D-600 or the big
Jadis. Given the heat the MA-2s throw off, I can't imagine a 400 watt version, if practicable, would
be practical in most homes.
**The Barber does clip rather more easily on the highs with most systems - its behavior with
the Genesis was atypical - but not if their impedance stays close to 8 ohms. And the Joule has the same
kind of clipping sound that the Atma-Sphere can be forced to exhibit, what I've called spritzing in an
effort to suggest a sort of tearing around the edges of high-powered, high octave orchestral instruments,
the aural equivalent of split ends.