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Nelson Pass First Watt F4 Power Amp Kit built power amp. The First Watt F4 is a classic Nelson PassFirst Watt design with JFET inputs and MOS-FET outputs. However, as with the other FW amps there is a twist here, namely that the F4 has no voltage gain. That means it’s essentially a buffer than can provide a full 25W class A output. This amp is low or no gain so needs a preamp with a decent output.
At £1,200, this is a strong deal versus the current used market: it sits well below the £2,230 25th percentile and far under the £2,640 median, so it reads as bargain territory rather than merely fair. For a First Watt amp, that’s especially appealing if the seller has kept it genuinely tidy and it’s working properly.
First Watt pieces are prized for their direct, highly resolving, low-power Class A sound, and the F4 is a particularly interesting one for systems that can use its purity and grip. The upside here is that you’re getting a respected Nelson Pass design at a price that leaves room for careful matching with speakers and preamp. I’d just confirm any included accessories and check for proper channel balance and quiet operation, but at this asking price it looks like a very worthwhile buy.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
First Watt emerged from the visionary mind of Nelson Pass, the renowned American audio engineer and founder of Pass Labs, in the early 2000s. Established as a boutique extension of his primary enterprise, it was conceived not as a conventional company but as a personal laboratory for experimental amplifier designs. Pass launched First Watt to delve into unconventional territories overlooked by mainstream hi-fi, drawing on his decades of expertise in single-ended triode and solid-state innovations, much like the legendary early Marantz and VFET amplifiers that inspired him.
The brand specializes exclusively in low-power Class A solid-state power amplifiers, typically delivering 10 to 25 watts per channel into 8 ohms—modest outputs by modern standards. Models like the SIT4, F1, and F7 employ zero-feedback topologies, JFETs, Static Induction Transistors (SITs), and even current-source architectures that prioritize purity over brute force. These handcrafted units eschew preamps, phono stages, or speakers, focusing instead on driving efficient, high-sensitivity loudspeakers with exceptional transparency and musicality.
First Watt commands a cult following among high-end audiophiles as a niche boutique icon, revered for its heretical yet revelatory sound that challenges voltage-source norms. Positioned at the pinnacle of purist amplification, its amplifiers—often priced around $4,000—appeal to discerning buyers seeking "a handful of quality watts" over high-power generality, cementing Pass's legacy in the vanguard of innovative, speaker-specific hi-fi.
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