Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier

An Instant Classic

Equipment report
Zesto Audio Andros PS1
Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier

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.


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