Tube Preamp Reviews

When I first met Luke Manley, proprietor of VTL, he and his father, David, with whom he ran the company at the time, had recently emigrated from the UK to California. I asked Luke how he liked the West Coast. "Great," he replied. "Much better parts availability." This was about 30 years ago, when I was just immersing myself in high-end audio at a high-toned level. Our exchange gave me a taste of the obsessions ahead, though Luke Manley's single-mindedness through the decades since has been more dogged than many—and, at the same time, less dogmatic.

This is a true story about a surprising 1W integrated amplifier—a push-pull, class-A, output-transformerless tube amp—that drove my DeVore Fidelity Orangutan O/93 speakers to 90dB average levels with grace, spiderweb detail, liquidity, and—unbelievably—a small degree of bass slam.

A quarter-century ago, when we were just getting into wine, my wife and I took a trip to Napa Valley. At one premium vineyard, we took a taste from the $20 bottle, then, for the hell of it, a taste from the $50 bottle. The first taste was nice; the second was alarming—an explosion of flavors, a gateway to sensory delights that we hadn't known could be had from a barrel of crushed grapes. We wobbled away, concerned that high-end wine might be a dangerous hobby.

The Lazarus, a slim, quite elegant unit finished in black with red and gray legends, lived up to its advance billing: it literally rose from the dead! Out of its coffin (ie, shipping box) and plugged into the wall, it showed no signs of life. Troubleshooting revealed a blown AC mains fuse. That in itself was not a major problem, but what worried me was the root cause of the trouble. Preamplifiers as a rule are not power-hungry, so a current surge at turn-on sufficient to destroy the 250mA slow-blow mains fuse appeared symptomatic of a major circuitry failure.

If you look at it from a distance and squint a little, Luxman's Classic CL-38u preamplifier ($4200) could almost be mistaken for that most classic of all classic hi-fi products, the Marantz Model 7C control center. The aluminum front panels of both models have, at their centers, a row of four distinctive toggle switches, flanked on each side by four control knobs. Even more noticeable are the stylish wood enclosures—standard on the Luxman, optional on the Marantz—which make both preamps appear ready for duty at the Playboy Mansion, ca 1963, or perhaps an appearance in a Life photo essay titled "At Home with Steve McQueen."

When I began my journey into audiophilia, I was in awe of the Audio Research Corporation's flagship SP preamplifiers. As I sat there in the early 1980s with my modest Apt Holman preamp, all of my friends had ARC SP6Bs. By today's standards, the SP6B was colored, did not portray a realistic soundstage, and lacked sufficient gain to amplify the low-output moving-coil cartridges of the day. But it had an intimacy in the midrange that was intoxicating. (Still considered a classic design by many, the SP6B's price on the used market has remained virtually unchanged for 30 years.) Then, still in the early '80s, ARC raised the bar with the SP-10 ($3700). It had 15 tubes and an outboard power supply, and set a new standard for delicacy, drama, and authority. (John Atkinson still has the SP10 he bought in 1984.)

When Carolyn Counnas, co-founder of Zesto Audio, contacted editor John Atkinson to ask about getting the Leto, the company's tubed line stage preamplifier ($7500), reviewed in Stereophile, JA suggested that I do the job. I'd recently reviewed competing designs from Nagra and VTL (see reviews in April 2013 and June 2013, respectively) and I was thrilled—I always look forward to hearing a tube preamp from a company I'm unfamiliar with, and besides, I'd seen pictures of the drop-dead-gorgeous Leto. After nearly 30 years of reviewing all sizes and pedigrees of preamps, power amps, and integrateds, I'm weary of staring at nondescript rectangular boxes in various shades of silver and black.