Ayre Acoustics K-1 preamplifier Paul Bolin, June 2002
From the time it appeared several years ago, the Ayre K-1 preamplifier was hailed by the audio world as a significant advance in the art and science of solid-state electronics. Stereophile's Wes Phillips was mightily impressed with it back in the March 1997 issue (Vol.20 No.3), as was I when I reviewed it for The Abso!ute Sound. For me, the K-1 was a landmark: the first piece of solid-state gear that this die-hard tubeophile heavily and unabashedly fell for. The K-1 quickly made its way into Stereophile's "Recommended Components," where it remained a fixture until the release of its revised version, the K-1x. J-10 didn't have to ask me twice to renew my acquaintance with the preamp and report on the differences.
Ayre's head man Charles Hansen lets no grass grow under his feet—the K-1 has been significantly upgraded twice in the last year or so. The initial upgrade, resulting in the K-1x designation, saw a significant reworking of the power supply (including a quadrupling of supply capacitance and a new circuit board made of the same high-speed material as the board carrying the audio circuitry), and the installation of multiple Ayre Conditioner filters on power-carrying lines. Topping it off was a new, detachable umbilical from Cardas that runs from the power supply to the head unit. Freshly re-kitted, the K-1x now empties the wallet of $6750 in basic line-stage configuration. Remote control is an extra $250, and a further $1600 equips the Ayre with dual-mono phono boards. Both options were fitted to the review sample.
But even as the K-1 was being transformed into the K-1x, Ayre was developing their V-5 power amplifier, and in mid-2001 a "new" K-1x was introduced to incorporate discoveries made during the V-5 project. These were in three areas: First, the ground-partitioning scheme was completely reworked to maximize isolation from outside interference for the main chassis, power supply, AC mains, and transformer. Second, additional RF filtering was applied to the AC mains and the DC power supplies for the audio and logic circuits. Third, new high-density polymer feet are used on both chassis for superior vibration isolation. While the retail price of this latest K-1x is the same as the original K-1x, owners of the latter can upgrade to the latest refinements for $450.
After arriving and settling in for a few days, I installed the K-1x in my reference system. LP playback was via a SOTA Cosmos turntable with a Graham 2.2 tonearm and Dynavector DRT XV-1 moving-coil cartridge. CDs were spun by Ayre's own D-1x DVD player and the stupefyingly good Classé Omega SACD/CD player. The phono stage was the Manley Labs Steelhead, and power amplifiers were the Manley Labs 250 Neo-Classic and Lamm ML1 monoblocks. The loudspeakers were my longtime references, the Apogee Duetta Signatures, biwired with Nordost Valhalla and SPM or Cardas Golden Reference. The phono interconnect was Hovland's Music Groove, and line-level interconnects were Nordost Valhalla and Cardas Golden Reference. Custom Power Cord Company Top Gun power cables were used for all power amps and the phono stage. I also used various footers and isolation bases, including titanium Nordost Pulsar Points and Arcici Ultra DynaFeet.
I immediately tested the Ayre's mettle with complex, large-scaled music. Magma's Mekanik Destruktiw Kommandoh (LP, A&M SP4396) has defeated many a piece of front-end electronics (footnote 1). This intensely percussive and densely layered music boasts multiple keyboards, a large brass section, mixed choir, vocal soloists, and full jazz-rock band. Cleanly sorting out the assembled forces is usually a nightmare, but for the Steelhead/K-1x combination it was a walk in the park. The Ayre was not only unfazed by this dense music, it peeled it open like an artichoke to reveal its architectural structure and myriad component parts.
Ataulfo Argenta's bravura traversal of Rimsky-Korsakov's Capriccio espagnol (LP, Decca/Speakers Corner SXL 2020) lit up my listening room through the Steelhead/K-1x. The almost sinful richness of the harp, trombones, and French horns contrasted with the clarity and rosiny sheen of the strings and the reedy bite of the oboe and bassoon in a vast, airy, beautifully described soundstage. The Ayre excelled at building the music on a firm foundation of bass, and consistently captured a cushion of acoustically charged air surrounding the basses and cellos on the Rimsky-Korsakov and on "Journey to the Line," from The Thin Red Line soundtrack (CD, RCA 63382-2). Voices were especially enjoyable through the K-1x.
Not that the rest of the spectrum was in the least slighted. The Grateful Dead's harmonies on American Beauty (LP, Warner Bros. WS 1893) and One From The Vault (CD, Grateful Dead GDCD40132) flowed from the speakers with easy, profound naturalness. Phil Lesh's loping bass-guitar counterpoint and the double drums of Mickey Hart and Bill Kreutzmann on One From The Vault were as clear, crisp, and clean as a mountain stream. Cymbals sparkled and shimmered, with not even a suggestion of grainy overlay.
I've always thought that one of the best indicators of a component's sonic neutrality is its ability to make each recording sound different from the last and the next. At this the K-1x excelled to an extraordinary degree, particularly when paired with the fabulous Lamm ML1 amplifiers. In every particular but the conductors' dramatic approaches, Argenta's Rimsky-Korsakov was a completely different experience from Paul Paray and the Detroit Symphony's recording of Dvorák's Symphony 9 (CD, Mercury Living Presence 434 417-2). The Ayre was able to differentiate between recordings so effectively because of its ability to dig deep into the soundscape and reproduce low-level detail. It did so not by hyping boundary definitions or etching the treble octaves, but its low noise and lack of haze and distortion allowed buried details to effortlessly emerge and find their levels within the overall musical picture. That the Ayre tracked the leading edges of transients like radar also played a large part in this. The K-1x's presentation was the audio equivalent of the sharp, deep-focus cinematography pioneered by Gregg Toland in Citizen Kane.
Like the K-1's, the K-1x's phono stage proved to be one of the best-kept secrets in audio. It had precisely the same sonic character as the line stage, with equal measures of pristine clarity and harmonic completeness. The phono stage didn't have quite the dynamic slam and epic scale of the $7300, standalone Manley Steelhead, but the performance of EveAnna Manley's pet monster in these respects is, in my experience, unique. Compared to more earthly phono stages, the K-1x's performance competed with all and should beat most. The Dynavector XV-1 cartridge presents most phono preamps with a fairly significant challenge. Its output is a relatively meager 320µV, but with the K-1x set to 60dB of gain and loaded at 100 ohms, backgrounds were completely silent and free of hum.
My white-label promo "six-eye" LP of Bruno Walter and the Columbia Symphony performing Beethoven's Symphony 8 (Columbia M2S 608) has been a special favorite for years. Walter's gemütlich but controlled performance was recorded in a spacious and reverberant acoustic, and the Ayre captured every last bit of that rich ambience, hanging on to the lengthy but delicate reverb trails like a rottweiler guarding a soup bone. Better still, the K-1x royally served Walter's richly humane and slightly playful interpretation, and reminded me in no uncertain terms why Walter's is still my favorite Beethoven.
After the Beethoven, I crossed to the other side of the musical street to hang with the Rolling Stones at the peak of their powers. Sticky Fingers (LP, Rolling Stones FC 40488) is usually considered a murky and indistinct mess, in sonic terms. But through the Ayre and the Lamms I could almost smell the Jack Daniel's fumes and cigarette smoke hanging in the studio air—the entire record was saturated with an ambience that lesser electronics simply cannot resolve. The multiple guitars of "Wild Horses" were beautifully rendered as distinctly separate instruments, each in its own space within the soundstage, and the pathos in Mick Jagger's voice was revealed as genuine rather than affected. On "Can't You Hear Me Knockin'," the K-1x absolutely nailed both Mick Taylor's exquisite silk-and-ground-glass guitar tone and Keith Richards' aggressively barking rhythm licks. What really raised my eyebrows was what the Ayre told me about Charlie Watts' drumming: The little quirks of his very subtle style of punctuation were effortlessly revealed as a fully integrated part of the musical tapestry. I've listened to this LP via the Lamms many times, but through the K-1x I heard a bonanza of musically meaningful detail that was new to me.
Virtually every quality I ascribe to the sound of the K-1x is connected to noise and distortion—or, more accurately, their absence. Charles Hansen's efforts to construct a totally isolated and unpolluted electrical environment in which his circuit can do its work have produced results that can properly be called breathtaking and enlightening. The K-1x provided a rather disturbing exhibition of how much subliminal-level grunge, hash, and noise is taken for granted as a part of the sound of even top-level high-end components. The K-1x added such a minimal amount of itself to the music passing through it that it was literally as if I was hearing for the first time much of the music described above.
But while its strictly sonic attributes deserve the highest praise, the Ayre's ability to go to the music's emotional heart was ultimately what made it so special. Its spectacular transparency to the source material put me far closer to the music than I had thought possible.
Does the Ayre K-1x, like the K-1, belong in Class A of Stereophile's "Recommended Components"? Are there bears in the woods? The K-1x is one of the very finest line stages any amount of money can buy, and its phono-stage performance is exceeded only by far more costly standalone units. As a full-function preamplifier, it offers a rock-solid, singularly excellent, and easy-to-live-with package. I unreservedly and enthusiastically recommend the K-1x, in whatever form, to anyone who wants to venture out to the cutting edge of sonic possibility.—Paul Bolin
Footnote 1: This album is not for everyone. Imagine a science-fiction oratorio sung in the original Klingon and scored jointly by Carl Orff and Frank Zappa, with Sun Ra as consulting arranger.