No Feedback, No Compromise: Soulnote A-2 ver.2

Founded by ex-Marantz engineer and director Norinaga Nakazawa, Soulnote designs "100% based on the actual sense of hearing" — and the Soulnote A-2 ver.2 is that philosophy at full volume. This is a completely non-NFB integrated amplifier: no global feedback loop of any kind, prioritising signal purity above tidy measurements. Nakazawa's team describes it, only half-joking, as "essentially a power amplifier equipped only with a selector and volume control." The result is the vivid, alive, three-dimensional sound that has made Soulnote a cult name among Japanese high-end enthusiasts.

Purist Circuitry, Obsessive Build

The A-2 ver.2 delivers 80 watts per channel into 8 ohms (160 W into 4 ohms) from a parallel push-pull output stage using high-speed TO-3P transistors precisely paired by hFE to eliminate the tonal smearing common to conventional designs. A four-stage Darlington driver gives it exceptional grip, while a non-impregnated large toroidal transformer runs at deliberately lowered voltage — trading maximum 8-ohm wattage for the instantaneous current that really matters into demanding, low-impedance loudspeakers. Everywhere you look, sound quality drives the engineering: a four-layer PCB with 70-micron copper, cables soldered directly to the boards with connectors eliminated from both signal and power paths, a chimney-type heatsink, and even a floating top cover and unsecured circuit board to keep vibration away from the music.

One Box, Four Amplifiers

A relay-switched balanced attenuator with high-precision resistors handles volume, sharpening imaging and low-level detail. And the A-2 ver.2 is really four amplifiers in one: use it as a stereo integrated, a bi-amp monaural integrated, a stereo power amplifier, or a bi-amp monaural power amp. In power-amp mode it bypasses the microcomputer, selector and volume entirely for the highest possible signal-to-noise ratio — a genuine upgrade path as your system grows.

Why You'll Love the Soulnote A-2 ver.2

• Completely non-NFB design — no global feedback, for vivid, natural, alive sound
• 80 W into 8 ohms (160 W into 4 ohms) — current-first power supply for tough loads
• hFE-matched parallel push-pull — high-speed TO-3P output devices, no tonal smearing
• Relay balanced volume — high-precision attenuator for pristine low-level detail
• Four amplifier modes — integrated, bi-amp mono, stereo power, bi-amp mono power
• Sound-first construction — direct-soldered wiring, floating cover, four-layer PCB
• Hand-built in Japan — Premium Silver or Premium Black, ~20 kg of engineering

Frequently Asked Questions

What does "non-NFB" mean, and why does Soulnote use it?

NFB stands for negative feedback — a technique most amplifiers use to lower measured distortion. Soulnote omits any global feedback loop because founder Norinaga Nakazawa believes it robs music of life and immediacy. The A-2 ver.2 is tuned entirely by ear, prioritising a vivid, three-dimensional sound over textbook numbers.

Can the A-2 ver.2 be used as a power amplifier or in bi-amp mode?

Yes. It offers four modes: stereo integrated, bi-amp monaural integrated, stereo power amplifier, and bi-amp monaural power amplifier. In power-amp mode it bypasses the selector and volume control for the highest signal-to-noise ratio.

Will it drive difficult speakers?

Its power supply is deliberately engineered for instantaneous current into low-impedance loads, and the four-stage Darlington driver gives strong control — so despite its "80 watt" rating it grips demanding speakers with authority.

Soulnote A-2 ver.2 Technical Specifications