Zesto Audio Andros PS1 Vacuum Tube Phono Preamplifier (TAS 222)

An Instant Classic

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.