A radio business bought out of Marantz.

Soulnote is the hi-fi brand of CSR, Inc. (株式会社CSR), a company in Sagamihara, Kanagawa Prefecture, south-west of Tokyo. According to CSR’s own company page, it was set up on 30 June 2004 and took over the wireless communications business of Nippon Marantz — the Japanese Marantz company, now part of D&M Holdings — through a management buyout. Its first products, the company says, were professional two-way radios, sold from September 2004; data-transmission systems and music-education equipment followed in 2005, and CSR began selling audio equipment in December 2006.

The brand’s origin is often told more simply than that. Soulnote’s European website says CSR “was founded in 2004 by the former members of Marantz Japan,” and Japanese Wikipedia names Norinaga Nakazawa (中澤矩長), whom reviewers describe as a former Marantz Japan director, as CSR’s representative director. The designer now most closely linked with the brand, Hideki Kato, is not its sole founder: he told the German magazine Hifi Statement in 2022 that he had worked at NEC and then Marantz, helped found the present company after Marantz’s reorganisation, and took full charge of Soulnote within CSR in 2016. Soulnote’s European site calls him “Chief Sound Manager”; Japanese coverage calls him chief designer.

Before Kato, Japanese dealer and press accounts credit the engineer Tetsu Suzuki with the early Soulnote range, and say he left in 2016 to start a brand of his own, Fundamental. AV Watch, in a sponsored feature in January 2026, dated the Soulnote brand to 2006 and said its early products were affordable before the 2016 turn toward high-end equipment.

Listening over measuring.

Soulnote’s design rule is stated plainly on its Japanese website: it “respects listening 100 percent,” rather than conventional wisdom or static measurements, and aims for a “living sound” by removing bottlenecks rather than “making a sound.” Its European site puts it as a preference for “dynamic performance” over static performance figures, and lists the techniques: a non-oversampling mode for digital-to-analogue conversion and amplifier circuits with no negative feedback. AV Watch reported in 2026 that all of the brand’s products use feedback-free amplification. Kato’s own summary, as quoted by Hifi Statement, is blunter: the more carefully a device is bred to produce good-looking data, the worse it sounds.

The current range is numbered in series. The flagship tier includes the M-3X monoblock power amplifier, launched in 2025 as an upgrade of the M-3 — owners can have an M-3 converted, the company says — and the E-3MC phono stage announced in June 2026. Below it sit the 2 series, refreshed as “ver.2” models in September 2025, and the 1 and 0 series, refreshed in October 2025; the A-1 and A-0 integrated amplifiers were reviewed by AV Watch in January 2026. Soulnote’s website reports that the M-3X and the A-2 ver.2 won Stereo Sound Grand Prix 2025 awards from Stereo Sound magazine, and that the E-2 ver.2 phono stage received a Bestpick award from the German magazine lite.

The company also warns buyers that its products are made in separate Japanese and overseas specifications, and that Japanese-market units re-exported by resellers may be unsafe abroad and may be refused repair; overseas buyers are told to buy from the regional distributor, which in Europe is IAD GmbH of Korschenbroich, Germany.

Japan’s boutique tradition.

Japan supports many small hi-fi makers, and several in this guide were started by people from the big names. Air Tight’s founder, Atsushi Miura, had been at Lux, now Luxman, before he set up A&M in 1986, according to a 2017 Phile Web interview. Leben’s Taku Hyodo also worked for Luxman, his company says, and Soulnote’s parent, CSR, was founded in 2004 by former members of Marantz Japan, according to Soulnote.

Others came from outside hi-fi. Aurorasound’s Shinobu Karaki spent almost 30 years at Texas Instruments Japan, his company says; Phasemation belongs to Kyodo Denshi Engineering, mainly an automotive-electronics firm; Kiso Acoustic was founded by a collector, Toru Hara.

Valve amplifiers remain central to this world: Zanden says it mainly makes products that use vacuum tubes, Leben calls itself a maker of tube amplification, and Air Tight says it holds to valve amplifiers. The Tokyo publisher Stereo Sound, whose founder held that no measuring instrument surpasses human sensibility, Japanese Wikipedia says, ran a quarterly devoted to valve equipment until October 2025. Its Grand Prix counts for small makers: Kiso Acoustic’s HB-1 won in 2009, and Phasemation says it was honoured in 2025.

The seven are not gathered in one district. Air Tight is in Takatsuki and Zanden in Kishiwada, both in Osaka Prefecture, and Leben in neighbouring Amagasaki; Phasemation and Aurorasound are in Yokohama, Soulnote elsewhere in Kanagawa, and Kiso Acoustic in Nakatsugawa, Gifu, according to their own websites and listings.

This guide sets out what can be checked about each brand — who founded it, who owns it, and what it says about where its products are made — and marks clearly what rests only on the company’s own word.

Designed in Sagamihara, built in Iwate.

Where the products are made is documented by visiting journalists rather than by the company’s own pages. The German magazine lite, after a factory visit published in May 2025, wrote that “all Soulnote components” are produced at Miyako, in northern Japan, at the factory of Miyako Marantz Ltd.; Fidelity magazine, visiting in 2023, also named Miyako Marantz. That factory has its own long Marantz history. Its website traces it to Miyako Standard, founded in October 1972 as a wholly owned subsidiary of Nippon Marantz and the first company attracted to the city of Miyako, Iwate; it became Miyako Audio in 1975 and began integrated audio production, and the present Miyako Marantz Ltd. was set up in July 2002. Today it describes itself as a contract electronics manufacturer in a “Marantz Electronics Group,” building audio, communications, beauty and medical equipment.

CSR itself has grown well beyond hi-fi. Its company page lists professional radios, karaoke equipment, music-education and beauty equipment, and distribution of PMC loudspeakers from the UK since 2016, of the STANDARD radio brand since 2020 and of Motorola Solutions radios since 2021. It reports 76 staff in March 2026 and names Kazuyoshi Takanashi as representative director — the title lite rendered as “President & CEO.” Its group companies include SOULNOTE Inc. (株式会社SOULNOTE), which the company page says was established in June 2023; Japanese Wikipedia instead says a SOULNOTE sales company was split off in July 2010, so we note both. Soulnote exhibited at the HIGH END show in Munich in 2025 and lists the Tokyo International Audio Show among its 2026 appearances.

For a design guide, Soulnote shows how a hi-fi brand can grow inside a company that began by making radios. Compare Marantz, the name its founders left, and Accuphase, another Japanese amplifier maker founded by engineers who left a larger company. For this guide we use black, brushed alloy and a deep red with a sans, an unofficial interpretation; no product or logo is reproduced.

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