Asked how to make a guitar, the celebrated luthier Wayne Henderson offered a straight-up answer: "Just get a pile of really nice wood and a whittling knife. Then you just carve away everything that isn't a guitar." (footnote 1)

The making of a preamplifier seems more or less the opposite. You start with a simple volume control and a couple of jacks, then add whatever you think constitutes a preamplifier. Choices might include electronic source switching, line-level gain, phono-level gain and equalization, tone controls, tone-defeat switches, a balance control, a headphone jack, an iPod input, and maybe even a digital-to-analog converter with a USB receiver. The sky is pretty much the limit.

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.