Zesto Audio Leto Preamplifier

Sonic Magic

Equipment report
Tubed preamplifiers
Zesto Audio Leto
Zesto Audio Leto Preamplifier

The entire midrange is beyond criticism, which I ascertained with the Anonymous Four’s Gloryland SACD. As I’ve said in other reviews, this is a real acid test for midrange resolution of fine distinctions in vocal character. The Four aim for the greatest possible blend, yet their voices are still subtly different from one another, which a revealing system will let you hear. A good cut for assessing this is the gospel hymn “Where We’ll Never Grow Old,” where the girls (no disrespect here—this is how they refer to themselves) are spread across the middle two-thirds of the soundstage, set back slightly, so that you hear a fair amount of air, but are still very present and slightly staggered front to back, so you should hear some depth between them. “Palmetto” opens with a solo singer who is joined by the group for the second verse, but here they are clustered even closer together and in a line, so there shouldn’t be a wide stereo spread and the soloist should sound clear of the others. Their blend is again little short of unbelievable, yet individual timbres are still perceivable with close listening. Another reason this recording is a reference of mine and why I was especially interested in hearing it through the Leto is that the sound is unusually pure and cold: There should be no “warmth” as such, but rather a cold, even chilly beauty. The Leto aced this SACD on every talking point without breaking a sweat.

The top end? Airy, extended, and natural. Listen to any recording that has really well-captured atmosphere or lots of high percussion and any concerns about the darkness that you’re supposed to find in tube units—and do in some—are immediately banished. Almost any jazz ensemble will do, or something like Christy Baron’s cover of “Mercy Street” on Steppin’ (Chesky SACD), which has, among other instruments, a rain stick on it. On The Christmas Revels, you can actually hear the sound ricochet off the walls so clearly that you can almost measure the size of the venue, while the collection of period and folk instruments will tell you volumes about a component’s ability to differentiate timbre and tone color. Again, the Leto’s handling of all this is second to none other’s.

One question the Leto raises is why electronic components that measure essentially ruler-flat, as this one does, should still sound different from one another, and sometimes not all that subtly. The only thing that occurs to me, and this is especially to the point when comparing tubes and solid-state, is differing harmonic-distortion profiles. Still after all these years, tubes distort differently from transistors, generally more pleasantly—even-ordered harmonic distortion as opposed to odd. Sometimes audiophiles want still more of tubes’ distinctive distortion because it’s so pleasing (hence the cults that develop around single-ended-triode amplifiers). The Leto’s specified distortion is so extremely low that experts I’ve consulted find it hard to believe it could contribute anything of consequence to the reproduction. But what little there is, perhaps because it remains tube in origin, may be responsible for a difficult-to-define impression of texture about the presentation that accounts for that organic quality I noticed in the Andros and hear in the Leto as well. I realize that this may contradict what I said earlier about freedom from sonic hype and electronic artifacts. So be it. Whatever the explanation, it results in a musicality and an impression of realism that are at once valid and authoritative yet without ever stepping outside the boundaries of sonic neutrality.

Subjective reviewing does not allow for components to be evaluated in isolation because the evaluations must be based on listening. Every now and then, however, components come along that serendipitously combine with other components so as to make for very special synergies that we clumsily call “magical.” This is what happened when I put the Leto into my current system, the amplifier and speaker complement of which consists in a Quad 909 amplifier and Quad ESL 2805 speakers (connected with AudioQuest interconnects and Kimber speaker cables, with a WyWires power cord). The Leto and 909 amplifier share similar characteristics of being unusually free from electromechanical artifacts and having vivid and engaging midranges, a full bottom end (the 909 very slightly on the warm side of neutral), and completely natural top ends. Their presentations also have an unusually high degree of body and dimensionality to them. The Quad 2805s are vanishingly low in coloration; state of the art for “speed,” transparency, and clarity; standard-setting for neutrality, openness, and that elusive sense of lifelikeness. I freely admit that when it comes to ultimate loudness and very deep bass-response, they are not only challenged but fall considerably short for some tastes or in rooms very much larger than mine. That granted, however, roll them all together and you have a system I could live with happily and never feel the need to make any changes for a very long time. I used other amplifiers throughout the listening sessions, and the fine qualities of the Leto were evident no matter what it was partnered with. But there was something that kept pulling me back to the Leto/909 combination, especially with the Quad ESLs: sonic magic indeed.

One of the last things I played before wrapping up the review is the DG “Originals” reissue of William Steinberg’s sensational recording of The Planets, musically and sonically one of the most dramatic performances of Holst’s suite, with a ferociously menacing realization of “Mars, Bringer of War.” When the cut ended, my six-year-old daughter, who had never heard it before, said, “Daddy, that music was scary. Please don’t play it again.” Samantha doubtless would have responded the same way if she had heard it on any good or better system. But I like to think her response had at least something to do with the sense of engagement, involvement, and sheer vitality the Leto brought to the system. I removed The Planets and put in Peter, Paul, and Mary’s album of children’s songs, which brought a smile to Sam’s face, though not before she asked me to program out “Puff, the Magic Dragon,” because, she said, “It makes me sad.”


Frequency response: 10Hz—100kHz, +/-1dB
Inputs: Three single-ended, two balanced
Noise: -100dB
Dimensions: 17" x 5" x 12"
Weight: 23 lbs.
Price: $7500

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

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