Nelson Pass built First Watt around a line from the reviewer Dick Olsher: "The first watt is the most important watt." He started it in 1998 as a "kitchen-table" effort to explore unusual low-power amplifiers, with the emphasis on sound quality. Each doubling of power makes music only a little louder, and Srajan Ebaen of 6moons points out that going from 100 watts to 200 gains no more than going from the first watt to the second. So Pass puts his effort into making that first watt as good as it can be, with small, simple circuits. The SIT-1 monoblock uses a single transistor, and Ebaen notes that "The rest is resistors and caps and a power transformer." Olsher found that the SIT-3 "blurred the line between solid-state and tube amplification," though Pass says the amps are not designed to mimic tubes. He made them for people who own efficient loudspeakers and "listen at reasonable levels."

Choose the speakers first. These amps want efficient ones, and for the F8 Olsher recommends an 8-ohm speaker of at least 90 dB sensitivity. Herb Reichert of Stereophile put a J2 on Zu's Soul Supremes and wrote that "my whole system lit up and danced." Steve Guttenberg played the SIT-4 on Pure Audio Project speakers and suggests it to owners of 300B tube amps. If your speakers use a single full-range driver, look at the F1 and F2, which were designed for them. A tube preamp makes a good partner. Olsher's favorite with the F8 was a tube preamp, and Guttenberg liked the SIT-4 even more with a restored 1970s Audio Research SP-3A. Give the amps plenty of air, since they run warm, and let them settle in. Olsher heard the SIT-3 improve after 30 to 60 minutes of warm-up. Most models come in limited runs, and Pass often releases the schematics once a run sells out. Gary Beard of Positive Feedback built his own F4.

Pass had a long career behind him when he started First Watt. He co-founded Threshold in 1974, the year he finished a physics degree at UC Davis, designed the Adcom GFA-555 in the mid-1980s, and founded Pass Labs in 1991. First Watt became the home for amplifiers he felt did not fit Pass Labs, and for years he assembled them himself. The first, the F1, was a 10-watt current-source amp. His boldest bet was the Static Induction Transistor, a power device that behaves much like a triode tube. Pass had his own made in silicon carbide, Ebaen reports, committing six figures to a first batch of untested parts. The SIT-1 and SIT-2 of 2012 became the most successful amps in First Watt's history, Olsher writes, and with about 500 of those transistors left Pass made the SIT-3, saying that "for about 250 people it will be the best." DIY builders know Pass as "Papa," and Guttenberg ended his SIT-4 review with "my hat's off to Nelson Pass."