Tube Preamp Reviews

Not so with Karin Winther conducting the Taby Church Chamber Choir on Hush! The Angels Are Singing (CD, First Impressions Music CD 001). The choir had a seductively angelic quality, and it was easy to delineate the individual layers of voices within the ensemble. The integration of the choir with the room acoustic was also extremely natural. But my single favorite vocal recording is of men's choir Cantus's performance of Eric Whitacre's Lux Aurumque, from While You Are Alive (CD, Cantus CTS-1208). The Jazz captured the perfect integration of the voices with an extraordinarily linear depiction of the subtlest microdynamics from pppp to p. Nagra makes a big deal of promoting the Jazz's low noise floor, and this recording showed it off quite elegantly. The preamp also showcased Cantus's uncanny precision of pitch in this piece.

Keeping within the Christmas spirit, I spun my favorite Christmas recording, Solid Brass's Christmas with Solid Brass (CD, Dorian DOR-90114). This recording has the most natural reproduction of French horn and trombone timbres that I've ever heard, and the Nagra's ruthless revelation of layers of uncolored detail in the lower midrange let me easily fool myself that horns had invaded my living room. The brasses were holographically placed across the soundstage, each instrument bathed in ambience. The Nagra also revealed a smooth transition from the nearfield envelope of the decays of the individual instruments' sounds to a clear delineation of the recording venue's acoustic.

In fact, the Jazz demonstrated an extraordinary ability to unravel the delicate nuances of individual instruments no matter how dense the orchestration. In an early recording by pianist Marilyn Crispell, "Rituel," from her Circles (CD, Victo 199), her quintet bursts with busily cacophonous energy, but I was still able to follow every one of the pianist's licks. Similarly, in the first movement of David Chesky's Violin Concerto, with soloist Tom Chiu and Anthony Aibel conducting Area 31, it was easy for me to follow each subtle woodwind line, even during fortissimo orchestral tuttis that include dramatic, crushing, and startlingly realistic-sounding timpani.

The Nagra also resolved transients with lightning-fast precision, but with no trace of hardness, blurring, or overhang. As I analyzed all the complex and difficult lines for mallet percussion in "Naval Aviation in Art?," from Frank Zappa's Läther (CD, Ryko 10574/76), I wondered which percussionist was playing: Ruth Underwood or Arthur Dyre Tripp? Underwood, I decided. (As this music was recorded during Zappa's confrontational period with manager Herb Cohen, there are no liner notes, at least in my copy, footnote 1.) On a more conventional recording of mallet percussion, and getting back into the Christmas spirit with John Zorn's most accessible recording, A Dreamers Christmas (CD, Tzadik 7393), percussionist Kenny Wollensen dishes out some pretty tasty vibes solos. Through the Jazz they sounded clean and shimmering, with a sense of body and natural decay.

Recordings that combine percussion with subtle low-level dynamics shone through the Nagra. In "Partial Truths/Four Impersonations," from his This Is Not a Clarinet (CD, Cantaloupe CA21001), clarinetist Evan Ziporyn uses his instrument's keys for percussion effects coupled with short bursts of breath. The precise dynamic envelope of this technique was captured by the Jazz exactly as I've heard Ziporyn perform it in concert.

The acid test for percussive realism is Charles Wuorinen conducting the New Jersey Percussion Ensemble in his own Ringing Changes (LP, Nonesuch H 71263). The Nagra resolved excellent detail with natural transients, while the recording venue was rendered with a great sense of air and space.

Realistic transient articulation goes hand in hand with high-frequency definition, extension, and delicacy, all of which the Nagra rendered in spades. With all recordings I played I heard a sparkling sense of clarity, cleanness, and delicacy throughout the Jazz's extended high-frequency range. Each note on electric guitarist Derek Bailey's Improvisation (CD, Ampersand 2) was reproduced with its own unique dynamic envelope; it was easy to unravel the high-frequency harmonic spectrum of each plucked string. And higher-volume electric guitar work, such as Mark Ribot's melodies in "Mow Mow," from The Dreamers, by John Zorn's Electric Masada band (CD, Tzadik TZ 11712), had the requisite searing bite and scream.

The Jazz's bass reproduction also impressed me, especially its rendition of double bass in jazz recordings. The midbass had a slightly rounded quality through the Nagra, but this wasn't a coloration; rather, it was a natural dynamic texture that enveloped each note of the instrument, and integrated perfectly with the sounds of higher-pitched instruments. Michael Elizado's bass in the Alex Cline Ensemble's Sparks Fly Upward (CD, Cryptogramophone CG102) was woody, uncolored, and dramatic; and Dave Holland's instrument in his Prime Directive (CD, ECM 1698) sounded clean and naturally warm.

The Nagra's ability to render linear and natural dynamic contrasts from ppp to fff was best exemplified by its reproduction of piano recordings. In "Isn't It Romantic," from the Bill Evans Trio's At Shelley's Manne-Hole, Hollywood, California (CD, JVC JVCXR-0036-2), the microdynamic phrasing of Evans's unique style was reproduced in all of its subtlety. At the higher end of the dynamic range, Paul Bley's fortissimo attacks in some of the more dramatic passages of his Close (CD, ESP ESPDISK 1021) had a sharpness and sense of drama that were quite realistic. There was also a sense of dynamic drama during the fortissimo passages of cellist J†nos Starker's recording of Locatelli's Sonata in D Major, with pianist György Sebök (CD, Mercury Living Presence 434 344-2).

But don't think the Jazz wasn't a great rock preamp—it perfectly integrated the richly holographic voice of Dana Fuchs with Jon Diamond's burning electric guitar riffs in the Dana Fuchs Band's latest, Love to Beg (CD, Ruf RUF 1167): coherent, together, and tight.

Comparisons
I compared the Nagra with my reference line stage, the Audio Valve Eklipse ($5699), as well as with Audio Research's Reference 5 SE ($12,995), which I reviewed in the February 2013 issue. The Audio Valve was as liquid and natural throughout its range as the Nagra, though I felt the Eklipse's midrange sounded slightly more forward. The Jazz also resolved a bit more inner detail and retrieved a tad more ambience. The Audio Valve's low-level dynamics equaled the Nagra's and its midbass was just as clean, though I felt the Eklipse's lower bass was more forceful. Through the Nagra, however, transients were more delicate, and there was a greater sense of purity and clarity in the highs.

ARC's Ref 5 SE created an even greater sense of space than did the Nagra, with even better resolution of detail and sharper, more articulate transients. There was also a greater sense of stage width and depth with the ARC, and its highs seemed even more extended than the excellent Nagra's, with even more articulate sibilants. The 5 SE also had a greater sense of decay, with more subtle gradations of dynamic inflections from pppp to p. However, the Nagra had more high-level dynamic slam in the midbass.

Summing up
The Nagra Jazz is a stunning, handmade jewel of a tubed line-stage preamplifier. Its build quality is indeed reminiscent of a fine Swiss watch, and its ergonomics and flexibility made it a joy to use. Most important, I enjoyed every piece of music I listened to through the Jazz, even when it ruthlessly revealed differences in recording quality. If you're considering buying a tubed preamp anywhere near the Jazz's price, put it on your short list.

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Footnote 1: My copy of Läther includes a 32-page booklet with liner notes and complete personnel credits: for this track, it's "FZ, guitar; Dave Parlato, bass; Terry Bozzio, drums; Emil Richards, percussion; Orchestra conducted by Michael Zearott."—Copy Editor