Leben RS30EQ Phono Stage

The Leben RS-30EQ phono preamplifier ($2695) incorporates a pair of common dual-triode tubes (12AT7) for phono gain, but breaks with tradition by using a CR-type equalization circuit rather than the more common negative-feedback type. Total gain is specified as 23.5dB, which is sufficient for moving-magnet pickups; an external transformer is recommended for use with moving-coil types. A silicon full-wave rectifier supplies heater voltage, while the rail is supplied by a 6X5GT rectifier tube.The RS-30EQ is just as well built as Leben’s CS300 integrated amplifier, with which I auditioned it, some of its parts being even more robust. A few of the RS-30EQ’s power-supply components are assembled on a small fiber-composite board—not a printed-circuit board—with most other parts supported by terminal strips. As with the CS300, everything was neatly wired, point-to-point. Unsurprisingly for a phono preamp—especially one that uses CR equalization—there were signs of extra shielding inside the RS-30EQ, and Leben says that a specially made “orient-core” power transformer was chosen for this product in an effort to minimize hum and noise.

Sound Quality
Because the Leben integrated amp lacks a phono stage, I supplemented the CS300 with the RS-30EQ, using a 1.5m-long Audio Note AN-Vx interconnect to go from the outputs of the latter to the inputs of the former. I preceded the Leben phono preamp with either an Auditorium 23 SPU Standard or Silvercore One-to-Ten step-up transformer, for use with low- and high-output MC pickups, respectively. The two Leben components sat directly on the wood shelves of my borrowed Box Furniture rack; only stock AC cords were used.

From the start, the Leben combination distinguished itself as a punchy and realistically textured amp with an especially deep, tight bottom end. Most stereo recordings sounded pleasantly large through the Leben, with instruments and voices maintaining good physical presence. The Leben was tonally well balanced overall, and although it had the sort of warmth and humanness I associate with tube amplification in general, it was free from egregious timbral colorations.

Rachmaninoff’s Vocalise, Op.34, from Analogue Productions’ recent 45rpm remastering of the recording by Donald Johanos and the Dallas Symphony Orchestra (Vox Turnabout TV 34145S), sounded lovely through the Leben, with sweet, delicate string tone and perfectly colorful woodwinds. Internote silences were reasonably “black,” though not nearly as stygian as with the best Shindo and Lamm electronics of my acquaintance. String tone, especially in the double basses, was also fine while playing through the Leben electronics a 1960 recording of Saint-Saëns’s Carnival of the Animals, with Beatrice Lillie, Skitch Henderson, and the London Symphony Orchestra (LP, Decca SXL 2218). The performance was sufficiently present that my dog expressed a keen interest in the various animal sounds therein (recorded for the occasion at the London Zoo).

The Leben didn’t have all the color and physicality of the Shindo separates when playing the curiously titled “Old Danger Field,” from Bill Monroe’s 1981 studio album Master of Bluegrass (LP, MCA 5214), but it was on the same page: enough to make the listening experience enjoyable as more than just hi-fi, if you know what I mean. Monroe’s mandolin didn’t leap from the mix, and the imaginary stage was spatially a bit flat overall—but it was rather wide and tall in comparison to that of the other amps, with a convincing sense of scale. Bass impact was excellent, as was the timing of the notes played by the upright bass. In the midrange and trebles, things clucked that ought to have clucked.

Conclusions
A quick tour through audio’s alternative fora uncovers a generous amount of praise for the Leben CS300—to which I can only add my admiration: This exceptionally well-made amp and its companion phono preamp sounded wonderful in my home. They were a pleasure to look at, a pleasure to use, and delightful to hear.

Combined, the retail price of my Shindo separates is approximately $27,500. For less than a quarter of that amount, Leben CS300 integrated and RS-30EQ phono preamp provided a lot more than a quarter of their musical and sonic abilities. They didn’t have all of the Shindos’ color, presence, internote silence, or magical sense of flow, but the Lebens had their wheels firmly planted on the same road.