Coincident Speaker Technology Partial Eclipse Series II Loudspeaker
And
Atma-Sphere Music Systems MA-1 Silver Edition Amplifier

It may seem a bit disproportionate, at least in a monetary sense, to pair a $9950 amplifier with a pair of speakers retailing for barely one-third the cost. But despite their relatively easy-on-the-wallet price tag and somewhat diminutive stature, the Series II Coincident Partial Eclipse proved to be a surprisingly worthy and synergistically intriguing match with the latest iteration of Atma-Sphere's MA-1 output-transformerless amp. I had the opportunity to audition the 2000 Golden Ear-award-winning MK II.2 MA-1 (see issue 127) several months prior to receiving the review sample, and as fine as that amplifier was, the Silver Edition sets the bar even higher with simply astonishing levels of clarity, focus, and detail retrieval, unrivaled by anything else I've heard to date.

First introduced back in 1987, the Silver Edition MA-1 celebrates 25 years of operation for the oldest and largest OTL manufacturer in the world. Atma-Sphere's founder, Ralph Karsten will readily admit he wasn't the first to market an output-transformerless amp (he duly recognizes Futterman for this accomplishment) but he does take credit for being the first to produce a practical and reliable OTL. Just to prove how bulletproof these amps really are, Ralph suggested I could lodge a quarter between the binding posts of a playing MA-1, while the waiting hand of an accomplice gave the system volume control a quick twist to wide open and back, all without inflicting any damage to components or speakers. Not being much of a daredevil, I opted to pass on this Fear Factor-style dead-shorting-your-amplifiers stunt, and just take his word for it. Although I had a few minor issues tubes and a blown fuse on the previous pair of MA-1 MK II.2s that I auditioned, the review sample performed flawlessly. Operation of the amp, including setting of the bias, is simple and straightforward as outlined in the owners manual. If someone as admittedly technically challenged as I can figure it out, anybody can.

According to Atma-Sphere, the MA-1's design is much like a pair of single-ended triode amplifiers wired together differentially. The Silver Edition is built on the same circuit concepts, but features a number of enhancements, the most obvious of which is the addition of a fifth driver tube, paralleled in the gain stage for increased bandwidth and lower distortion. The driver power supply is also now regulated, and plans are in the works for a user-selectable Class A/AB bias switch. The amp is currently rated at 140W pure Class A power into 8 ohms; a Class AB mode option would increase power to 175W while allowing for cooler operating temperatures-a definite Godsend during the summer months! Appearance-wise, the black power supply cover remains unchanged, while the former two-piece/two-tone main chassis has been replaced in favor of a single-piece version constructed entirely of non-magnetic stainless steel. Removing the bottom cover reveals Atma-Sphere's hallmark point-to-point construction along with custom-built wire, custom resistors, and custom Teflon capacitors.

The series II partial is designer Israel Blume's entry-level offering in the three-model Coincident Eclipse speaker line. As evidenced in both build quality and sound, this compact yet full-range monitor doesn't fall far from the Coincident family tree. The old titanium tweeter has been replaced in the Series II Partial with the identical Scanspeak Revelator silk-dome driver found in both the mid-model Super and top-of-the-line Total Eclipse; and though limited to a single bass driver, the Partial employs the same 8" side-firing woofer also found in the Super. Rounding out the driver complement is a new lightweight 5.25" woven-carbon-fiber flush-mount midrange cone, which replaces the previous surface-mount ceramic unit. Fit and finish of the dark cherry cabinet is first-rate, and the no-grille look gets my nod of approval as well.

Setting up the Partial Eclipses took a bit of experimentation, but in most respects the process was fairly straightforward. The Partial, like the Total, is a mirror image design, which allows for the flexibility of positioning the speakers with either the woofers facing towards each other or firing outward. In my smallish room, I preferred the Partials slightly toed-in with the woofers firing out, as this tended to broaden the soundstage. Due to the speaker's slim profile, it's pretty much essential-especially if there are pets or small children present-to secure the Partial with spikes or install them on a flat, hard surface other than carpet to prevent accidental tipping. Although both effectively anchored the speaker and noticeably improved performance in the process, the Symposium Svelte Shelf seemed slightly better than the optional Coincident brass spikes. This has been the case with other speakers as well, possibly due to the floor of my listening room being carpet over cement.

Rounding out the system was BAT's VK-3i, as well as an Atma-Sphere MP-3 preamp. Once again my Harmonic Technology Pro Silway 2's were the interconnects of the day, along with a pair of Elrod Signature 3 power cords. As incredibly open and detailed as the Atma-Sphere/Coincident combo was, the amazing Elrods managed to push the envelope even further. A pair of Coincident Total Reference (TRS) speaker cables, which I purchases some time ago and have been using with the Total, was a no-brainer choice with the Partial as well. Cable prices usually make me flinch, but in this case the $895 window sticker (per 6-foot pair) is money well spent if you want to hear the true potential of these speakers.

Although this review focuses on the MA-1/Coincident Partial combination, I also spent a good amount of time listening to the MA-1 paired with the more costly Coincident Total. It's fair to say the two speakers have far more similarities than differences, the smaller Partial just doing everything on a (you guessed it) smaller scale. That's not to say the Partial has a small sound, as quite the opposite is true. The expansive soundstage of the MA-1 easily filled my listening room via the Partial, but substituting the Total it blossomed twofold, filling every crack and crevice. The 94dB, 14-ohm Totals also had more finesse, and a greater sense of ease, which may be due to the difference in sensitivity between the two speakers. Although the MA-1 had no apparent difficulties driving the 92dB, 8-ohm Partial, OTLs are notorious for being more load sensitive than are amplifiers with transformers.

Regardless of which Coincident model I used, connection to the music is virtually instantaneous with the Silver Edition amps. The directness of tubes without an output transformer to get in the way makes for a sound that's truly unique, refreshing, intriguing, and exhilarating. Or put another way, it's a rush. Transient and tonal accuracy is nearly impeccable on Stanton Moore's "Fallin' of the Floor" [Flyn' the Koop, Blur Thumb Records]. And though the sound doesn't have the kind of sock-you-in-the-chest impact generally associated with solid-state gear, the music starts and stops on a proverbial dime, and you can feel the energy and excitement of seemingly unrestrained dynamics. Bass response is somewhat more limited on the Partial versus the Total, but still controlled, detailed, and well defined. And high frequencies are as open, airy, and uncompressed as I've ever heard.

The midrange is a breath of fresh air, harmonically rich, clean, clear, and exceptionally natural. No trace of artificial sweetener whatsoever with the MA-1. (My memory of the MK II.2 was of a slight background darkness that is now either gone altogether or barely noticeable.) The expansiveness of the soundstage is as big as all outdoors; exhilarating was the first word that popped into my head. I'm usually not big on Gospel music, but the articulation and focus on the ARC Choir's "Guide my Feet" [Walk With ME, Mapleshade] are absolutely stunning. Each voice of this Harlem a cappella choir was so distinct I swear I counted all 32 of them- and a few seemed to be standing on the sides of my listening room right next to me. The transients and dynamic contrasts were extraordinary. When the last hallelujah was finally sung, I was overcome by a sudden desire to go to church!

The MA-1 has to be the best example I've heard of a musical stream flowing uninterrupted from beginning to end, without calling any undue attention to itself at any given frequency range. I've always felt that music isn't something you just listen to, but rather something you interact with as well, at least on an emotional level. The Atma Sphere/Coincident combo is a pair of great facilitators in this interaction, allowing Jeff Bjorck's message of peace and calm through his solo piano performance "Pure Piano Panoramas" [Jeff Bjorck, BMI] to come alive in a more meaningful way than I've heard it before. For me, that's what this hobby is all about.

In addition to being a superb match with the MA-1 OTL, the Partial was equally comfortable mated with a variety of other amplifiers, including the Parasound JC-1, Meridian 559, BAT VK-75SE, and Ayre V-5x. The speakers didn't appear to have a preference for either tubes or solid-state, but were adept at revealing the strengths and weaknesses of whatever was fed into them. Two of my more affordable favorites were a pair of integrated offerings from Ayre Acoustics and Balanced Audio Technology. The 60W solid-state Ayre AX-7 could have used just a squeeze more juice to punch up the bottom end a bit, but the mids and highs were pure magic. The 150W SuperTubed BAT VK-300XSE wasn't quite as sweet, but still sonically compelling, and had the kind of speed and bass impact normally reserved for high-powered separate components.

The only other amplifier I've heard recently that compares to the Atma-Sphere MA-1 is another OTL, the Tenor 75W. Possibly due to the Tenor's slight forwardness and spectacular inner illumination, which is always just a hair's breath away from being bright, I found it a little easier to connect with the Atma-Sphere. The Tenor leans just a bit to the warm side, while the Atma-Sphere resides in the neutral zone with a broader and deeper soundstage as well. The Tenor's strong suit is a liveliness and almost uncontrolled exuberance that make everything else sound subdued in comparison, including the Atma-Sphere. Which one is better? I don't know. Which tastes better, chocolate or vanilla? That's truly a subjective call.

Perhaps what surprised me most about the Coincident Partials was being able to live with them-quite happily- for months on end without pining away for my reference Totals every time I turned the stereo on. That's not to say the Total isn't a better speaker, if you can afford it. But if you can't, the Partial is an attractive alternative that won't leave you feeling like your system is sonically compromised. And despite the disparities in size, price, and ultimate performance, the essence of what makes the MA-1 so special came through as loud and clear with the Partial as with the Total Eclipse. That's all you can really ask from any loudspeaker- to be truthful to the source.

About the truly exceptional Atma-Sphere MA-1-what can I say? As enthralled as I am with these amps, I still don't believe there's any such thing as the perfect component or Holy Grail of high-end audio. But when you plunk down your hard-earned bucks on this one, be ready to buckle up for the sonic joyride of a lifetime.

Sue Kraft




Designed By Science Driven By Passion
391 Woodland Acres Crescent, Maple, ON., L6A1G2
Tel: 647-221-1834
www.coincidentspeaker.com
iblume@coincidentspeaker.com