Tube Preamp Reviews

I've long been impressed by the design, construction, and sound of the tubed electronics produced by Vladimir Lamm, but I'd never had a Lamm Industries product in my house. So I asked for a review sample of Lamm's flagship line-stage preamplifier, the LL1 Signature.

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.

Branding can be powerful—a well-developed brand connotes strong images in the consumer's mind. Apple means ergonomics, elegance, ego. Fremer means analog, exuberance, fastidiousness. Rolex means Swiss-made, precision, expensive. Nagra means Swiss-made, precision, expensive.

In its comparatively few years in the marketplace, the line-level preamplifier appears to have established commercial parity with its full-function big brother. That this was inevitable was clear as far back as the mid-'80s. The advent of the CD and the proliferation of digital sources argued for a modular approach to preamp design. In such an environment, line-level sources (eg, DAT, CD, even analog tape) deserve special attention.

I must admit that, for a long time, I found it difficult to accept the idea that a major portion of one's audio budget should be spent on the preamplifier. Speakers, yes—they produce the sound; amps drive the speakers, so they're important. And source components? Well, everyone knows it's garbage in/garbage out. But a preamp? Even the name suggests something that's not quite the real thing, like pre-school, pre-med, or premature. Unlike amplifiers, they don't have to contend with loads that sometimes approach a short circuit, and heat dissipation is not normally a problem. What's the big deal?

At what point does a domestic audio product cease to be an appliance and assume a loftier place in one's home and heart?

We all can agree that a Bose Wave CD player sits at one end of that continuum, a Koetsu Jade Platinum phono cartridge at the other—but what of all the products in between? Scarcity, mode of manufacture, appearance, even sentimentality ("This is just like the one my father used to have!")—each plays a role, but there's no doubt that price tops the list: The more we pay, the more we love (footnote 1).