Soulnote is a high-end home audio brand by CSR, Inc. headquartered in Kanagawa, Japan. CSR was founded in 2004 by the former members of Marantz Japan. It has around 50 employees now. Hideki Kato, the Chief Sound Manager since 2016, has his long professional career since late eighties, having deeply involved in the development of the legendary A-10 amplifiers by NEC as well as the LHH series by Philips, but having kept himself staying behind the scene. Soulnote's first launch into Europe was a couple of years ago with the models SA300 / SC300 / SD300 / SC710 / SA730. However, the current line-up is based on totally different design concept from that of the previous models.
Through his long carrer as a designer of audio equipment both in analogue and digital areas, Kato has been struggling to find out the reason why the improvement in static performance and the sound quality in playback did not always correspond. Kato made a hypothesis about a counter-concept which he called dynamic performacne. The adoption of the NOS (non-oversampling) mode for PCM playback in digital-to-analogue conversion as well as a non-NFB (without negative feedback) circuit in amplifiers come from this hypothesis. Indeed these worsen the measurement result in static performance, but a remarkable improvement can be recognised in dynamic one.
Soulnote believes dynamic performance keeping accuracy of the original waveform on the time axis as the most important for music playback, which is, however, still unmeasurable by any of the conventional methods. At Soulnote, only listening dominates the determination and improvement of circuit, selection of parts and mechanical construction. This approach is a kind of antithesis against the supremacy of static performance.