Tube Preamp Reviews

Not knowing which pieces of wire or electronics were causing what, I borrowed the AudioQuest and Kubala-Sosna cables from JA. I then spent a couple of evenings connecting and disconnecting all four brands of cable on hand (such a glamorous life!), and settled on the following configuration: Nordost from turntable to phono preamp and from phono preamp to Rex II; Kubala-Sosna from CD player to Rex II; AudioQuest from Rex II to power amp; Nirvanas from power amp to speakers. This combo produced the best sound that I could eke from my system under the circumstances—and what a sound! That line I lifted from BAT's website about "the organic portrayal of music"? That was putting things mildly.

I listened to some great vocal albums: Ella Fitzgerald and Louis Armstrong's Ella & Louis (2 45rpm LPs, Verve/Analogue Productions AP-4033), Paul Simon's Hearts and Bones (LP, Warner Bros. 23946-1), Stevie Wonder's Original Musiquarium I (LP, Tamla 6002 TL2), and Lorraine Hunt Lieberman's disc of J.S. Bach's Cantatas BWV 82 and 199, with Craig Smith conducting the Orchestra of Emmanuel Music (CD, Nonesuch 79692-2). The singers beamed from the soundstage with a matter-of-fact, lifelike presence that I'd never heard from my system. I've written similar observations in other reviews; such is the embarrassment that comes with scaling ever-higher cliffs. (I try to convince my friends back on the ground: "No, I mean it—this view is really spectacular!") But the Rex II captured these singers' subtlest accents and modulations, their full-throated crescendos, their most softly whispered asides. It was spooky-palpable.

In real life, when a vocalist sings louder, a horn player blows harder, or a pianist steps on the sustain pedal, the decibels don't just rise—the soundwaves expand. The Rex II took me closer to that sensation than I'd ever felt from a recording in my living room.

The Rex II effortlessly unraveled harmonic details. At one point in "Hat and Beard," from Eric Dolphy's Out to Lunch (2 45rpm LPs, Blue Note/Music Matters Jazz 84161), Dolphy's bass clarinet and Richard Davis's double bass are played in unison. With many systems—even some very good ones—it takes some wincing concentration to distinguish the two, tonally and spatially. Through the Rex II, the players were instantly distinct—not as stick figures against a flat background, but rather as two 3D musicians playing together in the same room. Ditto for Dave Douglas's trumpet and Mark Feldman's violin in the title track of Douglas's Charms of the Night Sky (CD, Winter & Winter 910 015-2), another good test of a system's resolving powers (as well as a great, moody jazz album).

Listening to "Amelia," from Joni Mitchell's Hejira (LP, Asylum/Rhino R1 01087), not only did I hear new subtleties in her vocal phrasing, but the guitars and percussion all around and behind her (way behind her) pierced through with jolting vividness. I'd heard these sounds before, of course, but they'd never popped so distinctly from such tangible spaces on such a cohesive soundstage. This may be engineer Henry Lewy's best-sounding recording, and Rhino's vinyl reissue removes the compression that slightly marred the original.

In Maria Schneider's The Thompson Fields (CD, ArtistShare AS-0137), the great jazz-orchestra composer's finest work to date, the trumpets in the back row sounded as lifelike as the flutes and saxes in the front. The effect wasn't a nice, melded brass sound, but—even when they played softly—a row of musicians blowing their horns, their distinctive tones and colors mixing as an ensemble. Frank Kimbrough's piano projected just the right blend of percussive hammer and harmonic warmth. In the gorgeous opening track, "Walking by Flashlight," Scott Robinson's phrasing on alto clarinet expressed more subtle emotions than I'd heard before; it sounded more like he sounds in a live club—where I've heard him, and this band, many times. When Gary Versace squeezed the high notes from his accordion, they sounded glorious, pure and airy.

These revelations of detail extended to musical rhythm. I've listened to Miles Davis's Kind of Blue countless times, but a minute into the opening track, "So What," especially on Classic Records' 45rpm reissue (4 single-sided LPs, Columbia/Classic CS 8163), drummer Jimmy Cobb tapped his cymbal—at this point, still very quietly—with a slight oomph on the second and fourth beats of each bar that I'd never fully appreciated before. I'm not raving about some audiophile version of counting angels on the head of a pin; I'm talking about details that unveil more of the music's core—and more of the musicians mining that core.

While we're on Kind of Blue, I should add that I could also follow the pluck and thump of bassist Paul Chambers' every note, some of which plumb almost inaudibly deep on many systems, that the elements of pianist Bill Evans's tight chords emerged more clearly than I'd heard before, and that John Coltrane's tenor sax was blowing from way to the left of the left speaker, as it should be.

Finally, the Rex II displayed vast dynamic headroom. This is the sort of thing usually boasted by power amps, not preamps; perhaps it's all those toroidal transformers? No matter how loud an orchestral passage swelled, I never heard any distortion; the instruments, or at least the instrument sections, retained their distinct characters and colors.

My only caveat about the Rex II: The darkness I'd heard in the lower midrange at the start of my listening never completely lifted. But unlike with some electronics that display a trace of darkness, it didn't infect the rest of the audioband: the highs were luminous, the lowest bass notes deep and tuneful. Was I hearing inherent characteristics of tubes, artifacts produced by some other component in my system that the Rex II was revealing more ruthlessly than other preamps, or a reflection of the designers' taste? I don't know. If an audio component has a coloration (and most do), this coloration—a slightly dark, too-warm lower midrange, with stratospheric frequency extension and transparency elsewhere—is the coloration I like best. But others might find it a little ripe.

Toward the end of my listening, I got out an Allen wrench, removed the 16 hex screws holding the lid of the Rex II's power module in place, and flicked the switch that turns off the pair of 6C45 AC shunt-regulator tubes and turns on the 6H30s. In his review of the original version of the BAT—which he otherwise liked—Michael Fremer wrote that when he activated the 6H30s, "the Rex sounded 'tube-like' in the clichéd sense of the word: . . . somewhat soft overall, sluggish and thick in the bass," with a soundstage that was "narrowed and squeezed forward." I heard the same effects. When I played Maria Schneider's The Thompson Fields, Scott Robinson's clarinet still sounded pretty, but his subtle phrasing was now muffled, and the horns melded together as a homogeneous color with little sense of distinct blowing or tonal variation. I don't like the idea of letting consumers pick their flavor. (As Stephen Colbert's cranky character barked on his old Comedy Central show, "Pick a side, dammit!") But even conceding the merits of having some flexibility, I can't imagine anyone preferring the 6H30s' sound. Nor is it likely that anyone who can lay down $25,000 for a line preamp would own a system so bright and etch-y that it would need such massive mellowing.

Conclusion
While I'm in attack mode, I should say that the Rex II's owner's manual needs a rewrite: the all-too-few diagrams and photos are unlabeled, and some of the text's claims (eg, that the Rex II has a slot for an optional phono card) are wrong. Finally, the two boxes are pug-ugly: plain, black, bluntly rectangular, with no design flair. Even the buttons on the faceplate are too dark to read without a flashlight—which heightens the need for diagrams in the manual. At least the palm-size remote control is clearly marked.

But these are minor qualms. The Balanced Audio Technology Rex II is a wonder that has eked from my LPs and CDs more new things than any other component I've sampled in years—and not in a cold, analytical way, but with the full, coherent soul of music intact.