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Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier

Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier

Every now and then a component comes along that makes you reevaluate many of the values you bring to assessing audio equipment. Some personal examples include Quad ESL (of every vintage), Harbeth Monitor 40, and Spendor SP1/2 speakers; the Linn-Sondek (at a crucial moment in time, anyhow) and the SOTA turntables with vacuum hold- down; the Ortofon Windfeld pickup; the Basis Vector 4/2200 arm-turntable combination; the Super Audio Compact Disc; the late (very much lamented) Sigtech DSP device. These designs are not so much revolutionary as radical in the sense of returning you to origins or basics, reminding you of certain fundamental values that it’s too easy to take for granted or forget about as review products come and go.

Zesto Audio’s new Andros PS1 vacuum-tube phono preamplifier may be one such design, at least in the area of vinyl reproduction. It’s one of the loveliest-sounding electronic components I’ve ever had the pleasure of reviewing. Almost miraculously, it seems to exhibit virtually no discernable electro-mechanical artifacts. Its sound is unbelievably smooth and velvety; harmonically rich, full, and vividly textured; marvelously rounded, tactile, and dimensional, with great body and solidity; and completely natural in its musicality and freedom from any of the usual sonic hype, audiophile style. There is also an extraordinary homogeneity to the presentation, although a better word here might be “integrality,” as I wouldn’t want to suggest the Andros is in any way thick or undifferentiated. I mean, rather, to call attention to the way it reproduces musical events as organic, seamless wholes. There are, I believe, solid technical reasons why it sounds as it does, which I’ll get to later.

With well-recorded orchestral sources—I am now listening to the classic Stokowski recording of Liszt’s Hungarian Rhapsody No. 2 [Classic Records reissue]—the orchestra is spread across the front of the listening room, though by necessity restricted in size and volume. Regardless of what optimistic designers and starry-eyed copyrighters tell you, the literal scale and dynamics of a full symphony orchestra cannot be replicated in any domestic setting that remotely falls within the range of normal or typical. That said, however, the ease with which disbelief is here suspended is quite uncanny: the strings are set slightly behind the plane of the speakers with the rest of the ensemble stretching back behind them, all appearing as a cohesive group deployed in a setting that seems to be a real (as opposed to virtual) space. Yes, there is spot-miking and the top end is a little bright (whether owing to the mikes or the engineers’ equalization or both I cannot say), characteristics the Andros reveals, but not distractingly so, for this is a muscular recording of truly fabulous performances.

Perhaps more to the point is the sheer beauty of the sound, the richness of the orchestra, the texture of the instruments both individually and as an ensemble, the power of the brass, percussion, and low strings, the warmth of the cellos, the brilliance of the violins, the color of the winds. And despite his age, how rhythmically vital that old wizard Stokowski was! Interpretively, it’s a wildly imaginative, even willful ride, but realized with such style, virtuosity, and panache as to be irresistible, adjectives that also apply to the companion rhapsody, Enesco’s First Roumanian.

It being the season to be jolly, I hauled out a thirty-year favorite, the Hodie by Ralph Vaughan Williams in its first recording, conducted by David Willcocks. Vaughan Williams had long wanted to write a big Christmas piece, and this one has the feel of a dream realized. The forces, including full orchestra, two choirs, soloists, and organ, are huge, starting with a jubilant brass fanfare with choral interjections of “Nowell, Nowell” and ending with a spectacularly triumphant setting of Milton’s Ode on the Morning of Christ’s Nativity. The Andros did not disappoint, bringing this vintage EMI recording magnificently to life. Yet for all the size of the forces, it may be the intimate numbers that are the most deeply felt, in particular the meltingly beautiful “Lullaby” for children’s chorus and mezzo-soprano, here the incomparable Janet Baker. Notice, to take one small but telling example, how, almost imperceptibly, Baker’s voice emerges from the texture of the children’s voices.

 

Turning to popular voices, I went through several of the new Mobile Fidelity reissues of classic Sinatra, starting with Sinatra at the Sands. Hardly a great recording qua recording, it nevertheless does capture Sinatra at the peak of the Reprise years in a nightclub setting, the focus on the voice razor-sharp but still very attractive in a flesh-and-blood way, even if far too close up to be “realistic” (as with most live recordings in clubs, the perspectives are weird, with the audience appearing behind the performer). But so beautifully does the Andros reproduce The Voice that it’s easy to forget about all that audiophile stuff and just enjoy Sinatra, who is in great form even if the instrument is obviously no longer in the shape it was ten years earlier at Capitol (compare this “Angel Eyes” to the one on Only the Lonely).

A different baritone in Belafonte at Carnegie Hall [Classic Records reissue], that legendary voice at once husky and honeyed, likewise beautifully clean, clear, present, and superbly projected. The same for Julie London in Boxstar’s superlative reissue of Julie Is Her Name, reproduced with all the purity of pitch for which she is renowned. Soon I found myself bringing out records I hadn’t heard in much too long a time and wondering why I hadn’t: Growing Up in Hollywood Town, for example, Amanda McBroom’s first outing for Sheffield. I had all but forgotten the fantastic presence and immediacy of these direct-to-discs, to say nothing of their wide dynamic envelope (try the opening of “Amanda”). I was lucky enough once to hear McBroom at or near her prime in a small club in Santa Monica, doing her heart-wrenching “The Portrait,” the first cut on this Sheffield. Rarely have I heard a singer lay herself out so openly, with such raw and unflinching emotion. I’ve replayed that performance—more intense than the one on this Sheffield—in the theatre of my mind many times, but the recorded rendition is certainly intense enough so as not to suffer in the comparison.

Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier

Voices to instruments and Ben Webster’s glorious “How Long Has This Been Going On?” from the classic Ben and Sweets [Classic Records reissue], the same adjectives keep cropping up: smooth, velvety, yet Webster’s tenor sax still big, expansive, and voluptuous. Another sax, Sonny Rollins’ on Way Out West [Acoustic Sounds reissue], is vibrantly present. You could argue that the Andros is maybe a little too smooth here, because even when Rollins is relaxed and enjoying himself, as on this album, he’s still got a bit of bite to his tone, and so it is through the PS1, if ever so slightly ma non troppo. But turn to the Juilliard’s great sixties album of the Bartók quartets and you’ll find the Third reproduced with all the severity and acidity of tone for which this thorny piece is either famous or notorious. And despite the closeness of the recording, it nevertheless opens out with a surprising bloom and, perhaps owing to its very closeness, puts the performers in the room rather startlingly (especially if you get the playback levels just right, which doesn’t necessarily mean very loud). Regis Pasquier’s violin in his Harmonia Mundi set of the Bach Unaccompanied Partitas and Sonatas has the requisite warmth of tone and, where called for, brilliance.

If it seems that I have been talking mostly about the music and relatively little about the component, then you are on to my strategy. I’ve rarely auditioned a piece of equipment that has from the get-go made it harder for me to stay in reviewer mode as opposed to just plain music lover mode, causing me to scribble fewer (illegible) notes than I have in I can’t remember when. And I must confess that no one could be more surprised than myself by this, because, to put it frankly, I do not quite “get” the use of tubes for amplifying very low-level signals such as those from low-output moving coils. I make this admission not to my credit, only to put my bias out there as a context for my enthusiasm.

 The Andros is the first product from Zesto Audio, a new firm, based in Southern California, owned by George and Carolyn Counnas. George grew up in Great Britain where as a young man he designed vacuum-tube circuits and worked for DECCA Navigator, one of Britain’s largest electronics companies, as part of a research and development team designing airborne navigational systems for the Royal Air Force. But music was an abiding passion and he long wanted to design his own products, electing to begin with a phonostage. Despite what he freely acknowledges as the many advantages of digital, vinyl long ago won and still holds his heart. The same is true for vacuum-tube technology. “I started doing research on past phonostage designs going back to the original RCA circuits of the 1930s,” he says.

 

 “These guys got a lot of things right, even though their tools were slide rules and trial-and-error.” He claims some 71 circuit revisions and hundreds of parts upgrades before he arrived at the production Andros. Paying as much attention to the outside as the in, Counnas enlisted the help of his wife Carolyn (an artist) and Musky Mistry (an industrial designer) to come up with a look both unusual and unusually pretty. The black chassis consists of a lower layer adorned with a grey graphic of undulating curves on the fascia. The upper layer is shaped like a grand piano (viewed from the top) with a mirrored finish on the front edge that reflects the four softly glowing tubes located within the hollow curve. The graceful, gently curvy style belies the ruggedness, the chassis made from 16-guage steel and supported with IsoNode isolating feet. Parts quality and workmanship appear first-class.

The PS1 will accept both moving-magnet and moving-coil pickups (you can hook up two complete phono setups, provided one is high output, the other low), and there are even balanced inputs to parallel the RCA inputs (but RCA-only outputs). There are a two-position level switch for MCs and a novel grounding switch that allows you to isolate the ground if need be. Of great importance to me, Counnas is most definitely not a subscriber to the one-size-fits-all approach to loading, the PS1 offering eight options from 20 to 1000 ohms. Technical specifications are impressive, the price is $3900 (which includes 50 hours of factory burn-in), and each unit is “hand-built in the USA.”

As the Zesto factory is not far from where I live in Los Angeles, the Counnases themselves delivered the unit and set it up, though there was hardly any need for this, so easy is the job, out-of-the- box to music taking scarcely fifteen minutes. There is literally nothing to do but plug it in, attach all the appropriate signal cables (not provided), select pickup type (and loading option if applicable), turn it on, and put on a record. Since the unit is burned in at the factory, you might want to give the tubes fifteen or twenty minutes of warm up if you want to hear the Andros in all its glory the first time you cue stylus to groove (about the same warm-up time is required after it’s been off for awhile). Once you recover from the sheer beauty of that initial sound, what may strike you next is how quiet this thing is, noise being one reason for my bias against tube phonostages. No, you cannot crank the volume all the way up with your ear right against the speaker and hear silence (you can’t do that with most solid-state phonostages, either). But unless playback levels cross over into the insane, the impression of background blackness is without precedence in my experience of tube-based phonostages.

At the outset I said I believed there are good technical reasons why this unit sounds as it does, reasons not unrelated to that impression of low noise but not necessarily related to the use of tubes as such. Rather, I believe they have much to do with Counnas’ decision to use transformers to step up the low- output moving-coil signals. It has always surprised me that so many phono preamp designers eschew transformers in favor of active stages. To begin with, transformers are passive and do not generate electronic noise, which makes them, all other things being equal, quieter than even solid-state circuits, including those that are battery-powered. They are also far more tolerant of the vagaries of loading than active stages and suppress the resonances endemic to all moving coils much more effectively. Although some transformers are very expensive, there’s little evidence to suggest that they must be so to do their job effectively—design know-how definitely trumps exoticism of parts and materials.

Detractors of transformers will insist that they ring and that by comparison to active stages tend to be midrangy, with the frequency extremes suffering (highs rolled, bass soft or down in level), likewise dynamics, transparency, resolution, and “speed.” Those of us who like transformers grant some of these shortcomings as regards units of less than competent design but counter that none of them is intrinsic to the technology. We would also argue that transformers yield a more natural, musical, and altogether pleasing sound than any active stage.

 

As with so many audio debates, this one is unlikely to yield any sort of consensus. Each side can cite evidence in support of its position, even if the “evidence” consists in nothing more than listening impressions. Here’s my two dollars’ worth: I have for over twenty years used as one of my reference step-up devices Mike Sanders’ Quicksilver Audio transformer. This excellent design, priced at a mere $695, consistently makes for some of the most tonally neutral and musically natural reproduction of vinyl sources I know and is not deficient in any aspect or category of audio performance important to me. Its only potential drawback is that its fixed 470-ohm input impedance does not ideally load every MC, though it works very well for most I’ve used, including some I’ve regarded as reference caliber. Further, as noted, whatever their impedance specification, transformers do seem to damp or otherwise control MC resonances far better than inadequately loaded active stages do.

What I hear from the Andros PS1 are many of these same qualities—the ease, the relaxation, the unforced naturalness and musicality—only better, one large reason being that Counnas has designed the active stage to synergize optimally with the transformer (see Sidebar). And I surely find no sonic evidence here for any of the putative compromises at the frequency extremes: the organ pedal at the opening of the justly famous Decca Also Sprach Zarathustra (conducted by Zubin Mehta), where the 32Hz note is actually on the recording, is shudderingly powerful and never lost hold of while the full orchestra blazes above it. Articulation and definition, not to mention so-called “speed” and “punch”? I’ve already cited Stokowski’s Liszt. How about Soular Energy in the Pure Audiophile reissue? Ray Brown’s peerless bass offers no challenges the Andros isn’t up to, by which I mean that the foot-tapping brigade isn’t going to have much to complain about. Up at the top, the same applies to cymbals, brushes, hi-hats, bells, triangles—all these are set forth with an entirely persuasive naturalness. The truth is I consistently find the reproduction of components celebrated for their ability to “carry the tune” overly etched and articulated in a way that can sometimes be appealing but is certainly not realistic or natural. This is especially true of components reputed to reproduce rock music especially well: I often hear a thinnish upper bass; an overly pronounced, even brash upper midrange; and a rising top end, all of which accentuate the very qualities of rock music that, I suppose, its fans like and that can certainly convey an impression of considerable incisiveness even if it’s patently artificial. Music through the Andros betrays no such artifice or artificiality.

Transparency? Well, let me put it this way, while reviewing the Andros, music was always so involvingly there that “transparency” as a category of reproduction never occurred to me throughout the evaluations, which is to say that nothing made me think about it one way or another. There are many other components I’ve heard that excavate detail with rather more obviousness than the Andros, but none that has dug out anything the Andros has missed. On Way Out West, you clearly hear the players mutter to one another (or themselves) while they perform; on his recording of the Opus 131 with the full complement of the Vienna Philharmonic strings, Bernstein’s hushed breathing is still there, as loud as it needs it to be but no louder; on that spooky Belafonte recording of “Dark as a Dungeon,” when the thunderstorm approaches and it starts raining, the differentiation of sounds emanating from outside the studio and those from inside is wholly unambiguous, the storm manifestly approaches from a distance. When the rains starts, it’s light at first then obviously gets heavier as the song reaches its conclusion. I’ve rarely heard this last effect reproduced to more convincing effect than here, the rain sounding like real rain.

 Every now and then (mostly then) I sometimes wondered if the Andros could be a tad bit more dynamic, detailed, or “fast.” But when I played the same sources on components that brought out these qualities, they sounded all to varying degrees wrong: too much, too hyped, too everything . . . and soon found myself returning to the Andros for music as it really is. More than once I recalled an observation my colleague Robert Greene made of a component that especially struck his fancy: “It sounds totally unscrewed around with,” he said, which for him is fulsome praise indeed. And which brings me full circle to my opening theme and why the Andros made me wonder how many artifacts of reproduction we take for granted as being the only way things can be because they are so routinely the way things are, as opposed to the way they might be.

A hundred shy of four grand is nobody’s idea of a bargain for a stand- alone phonostage. But having been privileged to hear—at extended length in systems and surroundings with which I am intimately familiar—phono preamps costing tens of thousands of dollars that I would not choose over the PS1, I have no hesitation judging it to be worth its asking price, particularly when you factor in economy of scale, its domestic origin, its quality of parts, and its hand-built craftsmanship. The last thing I played before wrapping up this review was an old Musical Heritage Society recording called Christmas at Colorado State University, featuring the university’s (I assume) student choir and chamber orchestra and also its glorious Casavant Organ, widely recognized as one of the world’s greatest. The program opens with a powerful rendition for organ alone of Adeste Fidelis, which gives way to the chamber choir singing a cappella the French children’s carol “Il Est Né” (“He is Born”), and oh my, the way they sing it: with sweetness, innocence, and purity of tone, as befits the lovely melody and the lyrics, sounding out from medium distance, at once focused yet utterly open and radiantly clear. The music, the performance, the recording, and the reproduction were so beautiful that I played the cut three times before returning to the task of finishing my review.

SPECS & PRICING

Inputs: Moving magnet and moving coil
Noise: -75dB
MC stage: Transformer
Tube complement: Four JJ ECC 83S/12AX7
Frequency response: +/-0.5dB referenced to the RIAA curve
Dimensions: 17″ x 5″ x 12″
Weight: 20 lbs.
Price: $3900

Zesto Audio
Thousand Oaks, California
(805) 807-1840
zestoaudio.com

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