1929– founded by Masukichi Akai in 1929 as a manufacturer of radio components
1930’s– Business prospered while Masukichi’s eldest son, Saburo, grew up in the factory
1933– Father/Son team move their facilities from backyard premises to a new factory
1939– Ten days after getting married Saburo Akai (Son) receives his military enlistment papers
WW2– Masukichi sells premises and equipment to Sawafuji Electric Co
Post WW2– Saburo employed as an engineer at Sawafuji
1947– Saburo Akai buys the Kamata plant from Sawafuji. Changes the name to Akai Electric Company
1953-54 Akai begins to export goods bypassing wholesalers. Advertises in the American mag -Electronics with headline “Why not buy Akai technology?” generating inquiries from 5 interested companies. Roberts Electronics founded by Robert Metzner responds
1954– First Reel-Reel, the AT-1 model offered as a kit
1956– First manufactured R-R, the Akai 900.  Saburo takes a trip to the U.S. to study the market
1958– Deluxe Stereo Model produced
1960– New Marketing Plan- while continuing mass market, Akai pursues higher end investing heavily in R&D
1962– Licenses Cross Field technology ( better frequency response) from Tandberg and introduces the M-7
1964– Introduces the M-8
1970– Akai America sets up in California
1973– Saburo Akai dies in ski accident

1984 – Akai Professional, a new division of the company is formed to focus on Pro Audio.
The first product, the MG 1212, a 12 channel, 12 track recorder using a MK-20 VHS-like cartridge. With 10 minutes of 12 track recording at 19 cm per second or 20 minutes at 9.5 cm per second with dbx type-1 NR, recording quality rivaled 16 track machines using 1″ tape.
1985– Last Reel -Reel machine produced, the  GX-747

1991 – Akai leaves the audio industry. In the late 1980s, Akai employed 100,000 workers and had annual sales of US$5.2 billion.

November 2000 – The company filed for insolvency owing creditors US$1.1B

Answer Manufactory was based in Tokyo Japan

Aurex was a brand marketed by Toshiba, primarily in Japan and they sold a whole range of audio components including turntables, setbacks, speakers, FM tuners and more. The range of reel to reel tape recorders that they made was fairly limited.

Nippon Columbia of Kawasaki, Japan Produced tape recorders for their domestic market.

1896 – Frederick Whitney Horn, an American merchant, and owner of the F.W. Horn trading company, was involved in the import of tools (and machines) to Yokohama. He also began importing photographs and records produced by Columbia records.

1907 – He founded Japan-U.S. Recorders Manufacturing to stabilize the spread of gramophone production and disc standards.

1909 – Frederick Whitney Horn opened a factory producing discs. At the same time, he opened a recording studio, to be able to control the whole process.

1910 – Nippon Denki Onkyō Kabushikigaisha (Japan Electric Sound Company) was established by Frederick Whitney Horn in association with Japanese partners, as part of Nippon Chikuonki Shokai (Japan-US Recorders Manufacturing). Denki is Japanese for electric and Onkyo for sound.

They were the first Japanese company to sell gramophones, single-sided recording discs, and under the brand name “Nipponophone”, they became Japan’s first record label and produced Japan’s first record player.

1927– Japan Gramophone was purchased by Columbia Gramophone Ltd, and given its then name, Nippon Columbia. The company continued to serve the Far East market with records and players and began to branch out into radio broadcast equipment.

1928 – “Columbia” name was introduced when the company became Japan Columbia Recorders.

1938 – “Denon” was used by professional audio products taking the first syllables of Denki and Onkyo.

1939 – Developed Japan’s first professional disc recording machine, a twin-deck transportable device first professional-use disc recorder for the broadcasting industry the DR-148. It was delivered to Japan’s national broadcaster NHK in 1939, ready for the 1940 Tokyo Olympic Games.

1944 – The company officially became Japan Denki Onkyo Co., Ltd.

1945 – Denon made history when Emperor Hirohito’s speech to end World War II was recorded on a Denon device, the DP-17K. It was the first time the Japanese public had heard the Imperial voice. There was resistance to the transmission of the speech, and parts of the army stormed in the imperial palace to destroy the sound carriers. Therefore, the recordings were smuggled out of the palace and brought to the NHK headquarters, where the Emperor’s words were broadcast at noon on August 15, 1945. For a few years it was assumed that the original recording had been lost and that only a backup copy made by a technician secretly existed. However, later reappeared that it was kept in the NHK archive together with the original recording device to this day.

Post-World War II

1946 – Denon became a subsidiary of record company Nippon Columbia.

1947 – The company changes its name to Nippon Columbia, after absorbing Japan DENki Onkyo, it slowly becomes what we know today: DEN-ON.

1948 – R-23-A disc recorder/player was adopted as a standard by NHK, and installed in the company’s studios across Japan.

Technology began to change, with the advent of tape recorders and micro-groove discs (LP). Denon developed its first portable tape recorder that was far more convenient for reporting and interviewing than the vinyl recorders, which could at best be described as “portable”. NHK decided to use the R-28-F.

1949 – Collaboration of Tokyo Tsushin Kogyo (“Totsuko”, later Sony) and Nippon Denki Onkyo (later Denon) to produce a domestically made tape recorder using the Magnecord PT-6 model as reference. The PT-6 was already in use in Japanese broadcasting.

1951 – PT11 and PT-12 was introduced. These are the first domestically produced tape recorders for business use, and were put to use by broadcasting stations all over Japan.

 Nippon Columbia develops the world’s first stereo moving-coil cartridge.

1953 – Developed a professional-use tape recorder for the broadcasting industry.

1958 – Arrival of stereo records and record players.

1959 – Began commercial production of open-reel audio tapes.

1963 – Nippon Columbia decided to create a new brand of consumer and pro audio products then adopted the brand name “DENON”. Denon quickly became a by-work for high-fidelity excellence.

1964 – Commenced sales of audio cassette tapes

1966 – Launches its first headphone model, the SH-31.

1970 – Releases its direct-drive turntable for broadcast studios, the DN-302F and for the first time the Denon name began to appear on products aimed at the consumer.

The DP-5000 was introduced, a direct-drive motor unit for record players, to which buyers could add their own plinth, arm and cartridge

1971 – Started sales of hi-fi audio components, including turntables, amplifiers, tuners and loudspeakers

1972 – Denon’s first integrated amplifier, the PMA-500, was released

1976 – Heavyweight Denon direct-drive turntables were launched. The best-selling DP-3000 model, and in by the quartz-lock direct drive DP-7000.

1978 – Commenced sales of DENON DX audiocassette tapes.

1981 – Develop the world’s first CD player for professional use, the DN-3000F.

1985 – Denon’s first AV amplifier, the AVC-500

1990 – The company launches its DTR-2000G Digital Audio Tape (DAT) deck for pro recording

1993 – Arrival of flagship S1 series he S1 models for analog sound and digital audio.

1997 – Introduced and began sales of DVD-2000 Digital Video Discplayer, continuing active role in evolution of 5″” optical disc.

2002 – D&M Holdings Inc. was created.

2009 – the DVD-A1UD arrived – the world’s first ‘universal’ disc player

2017 – Sound United LLC completed the acquisition of D+M Holdings

Why wouldn’t Mitsubishi want to get involved with reel to reel tape recorders back in the 60’s? It seems that every significant Japanese electronics manufacturer saw an opportunity. Mitsubishi did get involved in a variety of different audio pursuits but never very seriously. Diatone which may have only been available in Japan is one of their brands.

1946 – Osaka Denki Onkyo K.K founded (not related to Nippon Denki Onkyo, which became Denon).

1960 – Dokorder name brand introduced with the PT-36B-W R-R, AC or battery operated and a PT-36BX

1971 – 9000 Series introduced with models 9010V, 9020V & the 9060H, a studio-type R-R

1972 – Stereo tape deck Dokorder 7500

1974 – Released 7140

1975 – Introduced 7100, 7060, 8010 and 8100, 4-track 2-channel tape deck. MK50A- stereo cassette tape deck/recorder.

1976 – Model 1140, with an automatic cue function called “Program Memory”

1120, a 4-track and 1122 a 2-track stereo mono tape deck

8020 as a home table top model that used smaller reels. It had the “Dub-a-Tape” that made a copy of a reel and was worth one tenth the price of the 1140.

1977 – Dokorder 7700 Released

1982 – Murata Manufacturing acquired 55% shares of Denki Onkyo.

1999 – The Denki Onkyo Company fully merged into Murata.

1949 Mr. S.Nishimura and Mr. H.Shinohara established Shinano Onkyo Institute in Japan to manufacture speakers.

1953 The “Foster” trade name was registered

1960 Makes speakers for Sony transistor radios

1962 Foster makes microphones

1965 Foster makes stereo radio tuners

1973  The Fostex Company was founded by Foster Electric Co.,Ltd. to brand speaker components from Foster and sell them direct to consumers and dealers

1978 Developed speakers for professional use and began to export worldwide

1981 Enters the professional recording market with three reel-to-reel models, the A-2, A-4 and the A-8 which was the first eight channel multitrack recorder using 1/4″ tape.

Fostex also introduced the Model 350 mixer and Model 250 four-track cassette multitrack recorder.

1983 X-15, portable cassette-based four track that ran on batteries.  B-16 First Fostex 16 track R-R using 1/2″ tape with Dolby C noise reduction

1986 The E-16 was introduced.

1990 Released G-16S. E-16 and G-16S (first R-R with Dolby S noise reduction)

1991 G-24S with 24 tracks into 1″ tape

Fostex transitioned to digital audio

1995 DMT-8, world’s first ‘digital multitracker’. Produced the RD-8 Alesis Digital Audio
Tape (ADAT) digital recorder 

Source

Made in Japan and marketed in Europe

The Fujiya Corporation of Japan was distributed in the US with an office at 405 Lexington Avenue NYC. Primarily producing portables, their models included EX-311 tube, FL-351, FL-523, FL-555, FL-771, MTR-252, TBR-31. It is very likely that the name Fujiya is an extension of the parent company’s name Fuji Denki (Fuji Electric) as we have found a tube tape recorder from the early days with that branding.

Apparently Griffin Boeki was a Company in Tokyo that branded Griffin tape recorders manufactured by Denon.

Perhaps this was as a result of a  US-based company similar to Freeman electronics asking for a customized build in the early 60s. Some promotional material indicates an office in Houston Texas. Japanese manufacturers at this time were very interested in opening up new markets

If anybody has any information beyond that which is posted on tapeheads by Dave In VA , that would be appreciated.

1910 – Founded by electrical engineer Namihei Odaira in Japan.  Company’s first product was Japan’s first 5-horsepower electric induction motor, initially developed for use in copper mining.

1916 – Completed 10,000-hp (7,355-kW) water turbine. Becoming a large industrial company making locomotives, transformers, elevators and other industrial products.

1920 – Incorporated as Hitachi (rising sun).

1924 – First large-scale DC electric locomotive to be manufactured in Japan

1949 – First U05 power excavator. Hitachi became known in part for its industrial use vehicles and equipment

1951 – Completed 6,500-kW Kaplan water turbine and 7,000-kVA AC generator (first umbrella-type generator made in Japan)

1958 – First transistor miniature radio

1959 – Established Hitachi America, Ltd.

1961 – Developed fully automatic washing machine

1964 – Completed first cars for the Shinkansen (Bullet Train)

1966 – Released portable tape recorder TRQ-520 and TRQ-330

1968 – TRQ-370 and TRQ-707 solid-state stereo tape deck

1969 – TRQ-737

1970’s Introduced TRQ 570 which was portable and still used reels.

1970 – TRQ-777 and TRQ-730D

1973 – Cassette tape recorder TRQ-225

1979 – TRQ-31

1978 – TV Radio Cassette Recorder K-50E was released

1982 – Established ‘Hitachi Europe Ltd.’. and succeeded in world’s first micro-level observation  of magnetic field by the use of electron beam holography.

1984 – First improved standard BWR to be made in Japan

1985 – Stereo cassette tape deck D-E17

2015 – Developed Hitachi AI Technology and launched solutions business using advanced AI  technologies

Not much is no known about this Japanese manufacturer which we can safely assume was located somewhere in Tokyo.

The Juli-Corder  Branded tape recorder listed here was found in Australia.

1946 – Kasuga Radio Co. Ltd. in Komagane City, Nagano Prefecture, Japan was founded by group of young entrepreneurs to manufacture sophisticated high-fidelity electronic components and amateur radio equipment. Kenwood, a combination of the name “Ken,” which is common in both America and Japan, and “Wood,” referenced the first overseas office in Hollywood and wood, a durable substance.

1947 – Manufacturing radio parts

1949 – Created the first-ever high-frequency transformer

1950 – Renamed Kasuga Radio Industry Corporation

1955 – Established Tokyo office and begins mass production of audio, communications and measuring equipment.

1957 – Developed and manufactured the first FM tuner in Japan.

1960 – Company was renamed Trio Corporation. Trio’s products were rebranded by the Lafayette Radio Company, with a focus on citizens’ band radio.

1962 – Launched the industry’s first transistor amplifier

1963 – The first overseas office in Los Angeles County, California, USA

1972 – Releases KW-5066 R-R stereo tape deck

1977 – Launches Kenwood’s series of Integrated Amplifiers and power amplifiers

1978 – Entered the commercial wireless radio equipment field

1980 – Released stereo cassette deck KX-1060 and launched car audio systems in the U.S.

1982 – Introduced portable FM radio.

1983 – First compact disc player.

1986 – Trio bought Kenwood and renamed itself Kenwood.

1991 – Released stereo double cassette deck KX-W8030. Developed the radio systems for F1 world championship race and began an official supplier contract with the Team McLaren.

1994 – Entered digital mobile phones

2008 – Kenwood made a deal to merge with JVC and formed a new holding company known as JVC/Kenwood.

Japanese company that selectively branded many other manufacturer’s products for the Japanese market.

So far we have found Teac Reel-Reel decks and Sony Elcaset Tape Decks branded as Lo-D.

Established by by Etsuro Nakamichi in 1948 as Nakamichi Research Corporation Ltd, the company is not widely known as a manufacturer of reel to reel tape recorders. In fact they were one of the early Japanese producers (1951) and marketed 2 tape recorders branded Fidela and Magic Tone. They also began producing tape recorder heads in 1957.

This obscure Japanese website lists the Magic tone as a 1951 model and the following 15 models of Fidela reel to reel tape recorders – 11, 22, 33, 55, studio 77, studio 77D, studio 300D, studio 300DS, 720, 780, 807, Gem Sonic 807, 860, 920, 960. Maybe Gem Sonic was a 3rd brand?

Rumour has it that starting in 1967 and for a number of years, the following US companies bought electronics or complete tape recorders from Nak – Ampex (just certain models) KLH, Harman Kardon, Advent, Fisher, ELAC, Sylvania, Concord and Motorola.

Nakamichi made the electronics for the KLH Models 40 and 41, both 3 motor, 3 head machines assembled in the US and it is believed that Concord made the transports.

National brand produced by the Matsushita Electric Industrial Co.

The Nitttiku Kogyo Company Produced tube-based tape recorders in the late 1950’s In Japan but does not appear to have continued Into the period where Japanese tape recorders prevailed in the marketplace.

The Oki Electric industry Co. Ltd. Produced tape recorders branded as Oki and OkiCorder which were the portable models.

1964 – Former Teac Engineer, Masayuki Hosoda founded Otari Corp. making tape recorders, mixing consoles and duplicating machines

1966 – Company’s first product DP-1000 high-speed tape duplicator

1967 – MX-5000, first multi-track recorder

1968 – MTR-60, first master tape recorder

1970 – DP 5000 and MX-7000 R-R were released

1974 – Developed TD7500

1977 – MTR 90 R-R

1978 – MX5050 B2 HD

1979 – Videotape loader VL-100

1980 – Established the subsidiary Otaritec Corporation producing professional audio equipment

1981 – MX5050 BQII

1984 – MTR-10 and MTR-12

1986 – Released MX-80 multitrack tape recorder and BTR-5 broadcast tape recorder. Launched first digital recording system.

1987 – Master tape recorder MX-55 and the multitrack tape recorder MTR-100A

1989 – Renamed as Otari Inc. and acquired Sound Workshop in the United States.

Introduced MX50 and eight-millimeter tape loaders the T-820 and VL-811

1990 – T-320II, videotape loader

2014 – Continues to make magnetic tape storage machines. The MTR-15DAS2/4 is a current model high-speed analog tape player for reel-to-reel type analog audio tape

1936– Munoz Matsumoto (1905–1988) founded the Fukuin Shokai Denki Seisakusho company in Japan. The son of missionary, Matsumoto’s company name means “Blessed Sound Electric Company”.
1937– Matsumoto builds the A-8 dynamic speaker, based on a Philco model he heard earlier, and named it the “pioneer”
1938– Matsumoto started the Fukuin Shokai Denki Seisakusho Company (FSDSC), making speakers in his garage, then started a small factory that repaired radios and speakers
1953– FSDSC released the PE-8 Hi-Fi Speaker.
1961– The FSDSC name is changed to Pioneer Electronic Corporation
1962– Pioneer made the world’s first separate channel stereo system with detachable speakers
1964– Pioneer released S-71X modular stereo set, making Pioneer a recognizable name with its success
1966– Pioneer marketed its automotive stereo players through Craig-Panorama

1975– Pioneer made its first component car stereo
1976– Pioneer releases the RT 707 &  RT 2044
1979– Consumer Laser Disc  introduced. Pioneer released the RT-909, and made them until 1984

1982– Pioneer made its first CD player, marking the end of its R-R recorder efforts

1947 Sansui founded in Japan, initially manufactured transformers. It is part of Grande Holdings, a Chinese Hong Kong-based conglomerate, which also owns Japanese brands Akai and Nakamichi

1960s Sansui had developed a reputation for making serious audio components, especially amplifiers and tuners

1970’s Sansui makes multi track vertical reel to reel recorders

1980’s As the brand lost sales were lost to competitors, it began to lose visibility in the United States around, and then focused on manufacturing high-end components in Japan.

Sept. 1945  Masaru Ibuka established “Tokyo Tsushin Kenkyujo”(Totsuken), or “Tokyo Telecommunications Research Institute” with old friend Akio Morita.  Tokyo Tsushin Kogyo, perhaps a short form, is the name on some of the early tape recorders made up until 1954.

1946  The company began experimenting with wire recording and were able to see a demonstration of a Wilcox-Gay tape recorder. The NHK (national broadcasting station) asked them to convert military-use wireless equipment into relay receivers for broadcasting applications, to restore a national broadcasting network. The company relocated to a new factory at Gotenyama, in Shinagawa.

1947- 48 Impressed with an American wire recorder, Totsuko built their own. A friend in the United States gave Morita a Webster recorder kit that used stainless steel wire. Nobutoshi Kihara, an ex-student of Ibuka’s at the Mechanical Engineering Department of Waseda University completed the kit assembly with an amplifier.
While still working on the wire recorder, a member of the Civil Information and Education (CIE) section showed them a tape recorder. The sound was remarkably better than that of the wire recorder, and Ibuka and Morita resolved to make a tape recorder no matter how difficult it might be. The Totsuko engineers began experimenting with tape, trying many variations of magnetic coating, bases and methods of bonding, at their new Yama-no-ue factory until finally towards the end of 1949 they suceeded in making a suitable quarter inch magnetic tape.

1949 The first prototype (Japan’s first tape recorder) completed in September 1949, was a vertically designed tape recorder modeled after the “Magnecorder,” which was already in production in the United States. 

1950 The G and A type prototypes were made in January and February. The G-type was designed for institutional use, with a recording time of 1 hour while the A-type was designed for home-use, with a recording time of 30 minutes. Although the A-type product did not advance beyond prototype stage, its concept was fully incorporated into the H-type, which was later marketed as the first home-use tape recorder.
In marketing the G-type tape recorder, Totsuko registered it under the trademark name of “Tapecorder.” At the same time, the Totsuko tape was commercially named “SONI-TAPE.

1951 G-type product variations. The G-type “A” incorporated a limiting amplifier for better articulation of sound nuances. The G-type “B” designed with emphasis on frequency characteristics and sound fidelity. All the G-type tape recorders were very heavy.

 Totsuko engaged the services of an industrial designer, Sori Yanagi to design Sony’s first consumer model the H Type, launched in March 1951 (a portable version of the G Type) which included an external mic and came in a suitcase weighing 13kg (a third of the original G-type) .
One of the keys to Totsuko’s success in tape recorders was the fact that they had patent on AC bias recording which gave them a monopoly in the Japanese market.

March 1952  Ibuka visits the United States for a three-month inspection tour to see how American consumers used tape recorders. At the time, tape recorder sales in Japan were limited to the educational market. Ibuka keenly wanted to widen this market and if possible, he wanted to observe how tape recorders were manufactured by American companies on their assembly lines.

Sony introduced the Type M, a portable recorder developed for professional broadcast use. Radio programs that interviewed ordinary people on the street using the M Type enjoyed a surge in popularity.

1954 Sony introduced the TC-301. It was the first small tape recorder designed for the consumer market and was the start of the mass produced Sony electronic products. Later in the year a 401 was released and is branded Tokyo Tsushin Kogyo (included below)

1955 The first Sony-branded product, the TR-55 transistor radio introduced

1950’s Sony’s TR-63 radio sold an estimated 100,000 units from 1955-1968

1957 The company name was officially changed to Sony. The name is a mix of the Latin word “Sonus” and “Sonny”, a familiar American term at the time. The 553 recorder was the first Sony reel to reel sold in America

1959 Sony introduced the Model 101, a version of the H Type that was more compact and used 7-inch reels

1960 Sony co-founder Akio Morita founded Sony Corporation of America

1961 Sony introduced the TC-777, the first fully transistorized Japanese reel-to-reel recorder with a built-in amp. Developed for the home, it used buttons instead of levers and was affectionately known as “Three Sevens”

1964 Sony launched the TC-263D reel-to-reel recorder with the familiar vertical form factor

1969 Sony introduced the TC-1150 tape recorder with a built-in condenser mic. This model used the compact cassette format and was very small and portable for its time.

1975 Sony launched the Betamax videocassette recording format

1977 Sony made its last reel to reel tape recorder, the TC-765, which would continue to be sold into the early 80s

1979 The Sony Walkman was introduced, using the compact cassette format. The Walkman was wildly successful across a huge number of models and has been given credit for keeping analog alive with prerecorded tapes achieving sales levels in the mid-80s that were previously unheard of. Some record companies reported over 50% of their sales were in cassettes around that time.

1982 Sony introduced the Digital Audio Stationary Head (DASH) standard for multitrack studio recording and mastering, makes 2 DASH recorders, the 24 track PCM3324S and the 48 track PCM3348HR

Sony History From the Sony website (Part 2- Tape Recorder Specific)

Full Sony History

This brand was manufactured by the Nihon Recording Co. in Tokyo Japan. They appear to be in early entrant into the market in the 1950’s that did not continue.

There seems to be a fair bit of duplication on the Teac history story and it seemed best at this point to put forth a variety of links to some of the better efforts to capture the interesting story. Perhaps we will build out a more definitive history, when more unique information becomes available.

TEAC – The History of Recording and Sound

Museum of magnetic sound recording – Teac

TascamForums.com

1918 – Panasonic was founded in by Konosuke Matsushita first selling duplex lamp sockets.

1965 – Panasonic started to produce a variety of hi-fi products under the Technics name brand. The first product out of the gate, The Technics 1 speaker.

1969 – The Technics name came to wider prominence with sales of turntables for the professional market

1970 – Produces the worlds first Direct Drive Turntable, the SP-10,  Tonearm not included

1972 – Technics introduced the first auto reverse system in a cassette deck with the RS-277US. Introduces SL-1200 Direct Drive Turntable which sold over 3.5 million units and is still popular today.

1973 – Manufactures the first three-head cassette deck ever made, the RS-279US

1976 – The Technics RS-1500 was introduced. The 1500 2 track was heavily advertised and sold well. Technics also sold other Isolated Loop transport models, the RS-1506 4 track,  RS-1520 Semi Pro 2 Track, RS-1700 Auto-Reverse and the rare RS-1800. These models were built until 1987

1979 –   SL-10 Unique small Turntable that was the size of a LP jacket. Design awards followed and has been in the Museum of Modern Art ever since

1988 – SST-10 Sound space speakers with a twin load horn also made it to the design collection of the MOMA

2000 – DVD-A10 The world’s first DVD audio player

1989 – Continues to produce turntables where many other companies are leaving the format SL-1200MK3 , 1997 SL-1200MK4 , 2002 SL-1200MK5, 2008 SL-1200MK6

2015 – 50th Anniversary- The Technics brand was revived with new high-end turntables

2016 – SL-1200G

The Kasuga Radio Co. Ltd. in Komagane City, was founded in 1946 and renamed Trio Corporation in 1960. During that decade they made a lot of Radio Shack & Lafayette products. Kenwood was another brand that they pioneered and later in the 60’s they phased out Trio branding and focused on Kenwood.

Not much is known about what appears to be a serious broadcast tape recorder manufacturer in  Japan.

This  blog post could be  a good start to begin research.