Tracing the journey of a brand that won over the world
TDK is one of Japan’s leading cassette manufacturers and a brand that won over the world. It introduced many landmark products and contributed greatly to better sound quality and the spread of cassettes. Let us look back at that history chronologically.
Text: Yasukazu Otsuka (大塚康一)
June 1966, Production of Japan’s first cassette as an OEM product for Matsushita
Releasing SD, the world’s first music cassette
TDK, originally named Tokyo Denki Kagaku Kogyo, began as a manufacturer of the magnetic material ferrite. Its name is said to honor the electrochemistry department at Tokyo Institute of Technology, to which ferrite inventors Yogoro Kato (加藤与五郎) and Takeshi Takei (武井武) belonged. Applying that technology, the company began making magnetic tape in 1952. In March 1966, it signed an agreement with Philips, which had made its cassette-tape patent available royalty-free. In June 1966, TDK produced Japan’s first cassette as an OEM product for Matsushita Electric. It subsequently made OEM cassettes for various manufacturers, supplying America’s GE and Japan’s Yamaha, Toshiba, Trio (now JVC Kenwood), Luxman, Nakamichi and others. Other companies beginning cassette production in Japan at the time included Sony, Hitachi Maxell and Fuji Photo Film.
In September 1966, having waited for its moment, TDK released Synchro Cassette under its own brand. Japan’s cassette era had begun. The name had originally been used for the company’s open-reel tape. In March 1968, the brand changed to the company name TDK, with packaging redesigned around the diamond corporate symbol.
September 1968 brought the US release, ahead of other markets, of SD, the world’s first cassette for recording and playing music. This was a major turning point for TDK and for the cassette itself. Even earlier, its presentation at New York’s CES (Consumer Electronics Show) had met with thunderous applause. The first LH (Low Noise High Output) tape in cassette history received enthusiastic reviews in contemporary American hi-fi magazines and other publications.
SD stands for Super Dynamic. Its magnetic material was a fine, needle-shaped goethite developed by Toda Kogyo with Kyoto University professor Toshio Takada (高田利夫), offering the world’s highest ability to retain magnetization. TDK bought and refined this material while developing open-reel tape, but decided to develop a cassette tape urgently to exploit its excellent properties. Previously, cassette frequency response had reached only about 10,000 Hz. SD, remarkably, could record and reproduce up to 20,000 Hz. The Compact Cassette, previously considered a medium for ordinary recordings such as meetings, consequently gained widespread recognition as a proper music-recording medium. Other companies subsequently developed and released dedicated high-fidelity, high-performance music tapes too.
Japan’s sales launch of SD, the world’s first music cassette, came in March 1969. Highly praised by reviewers, audio manufacturers and enthusiasts, SD also became a reference tape for cassette-recorder manufacturers.
SD is even said to have been used on Apollo 11, suggesting its high reliability. It initially had gold-toned packaging with the diamond logo. As improvements were made and to distinguish it from competitors, the packaging became striped and cases became entirely plastic.
In December of that year, the Chikumagawa factory dedicated to magnetic tape was completed. Construction of the California tape factory was completed in September 1972.
Developing high-performance AVILYN and new magnetic materials
November 1973. The high-performance magnetic material AVILYN, developed by Dr. Yasuo Imaoka (今岡保郎) and Shinji Umeki (梅木信治), was iron oxide with added cobalt. It was innovative: adjusting the amount of additive suited it to different applications, including audio and video. By 1972, various companies had already introduced High Position (Type II) tapes using a chromium-dioxide recording material developed by America’s DuPont in 1961. TDK also bought it and released its first Chrome tape, KR (Krom-O2). However, quality was inconsistent, and DuPont prioritized Sony’s supplies. With these and other circumstances leaving little room for retreat, TDK planned its own development. It began work on a High Position tape that would not infringe DuPont’s patent, finally succeeding in releasing SA using AVILYN.
SA for High Position was released in March 1975. SA stands for Super Avilyn. Having astonished the world with the Normal tape SD, TDK did so again with SA. Its superior frequency response to Chrome tape became a talking point. Surpassing Western-origin chromium-dioxide performance helped pave the way for Japan’s subsequent leadership in magnetic materials and tape manufacturing.
AD and ED were released in March 1977. AD was the Normal successor to SD, its name abbreviating Acoustic Dynamic. The slogan then was Penetrating high-frequency clarity, and the choice of Miles Davis as its advertising personality also surprised people. SD production ended as competing products multiplied. AD adopted new high-performance Linear Ferric magnetic material (リニアフェリック). This outstanding Normal tape delivered crisp, clear sound with a flat response extending into high frequencies. AD subsequently received numerous improvements and repeated updates, remaining in production until 1995. It could truly be called a reference among Normal tapes, as SD had once described itself.
ED, meanwhile, stood for EXTRA DYNAMIC and was the world’s first cassette using magnetite. Magnetite surpassed the widely used gamma-hematite in performance, but suffered from chemical instability and a tendency toward print-through. TDK overcame these problems with proprietary technology and put the material to practical use.
The new SA appeared in April 1978. D, AD and OD followed in 1979 as part of the New Dynamic Series. OD succeeded ED as the top-grade Normal Position cassette dedicated to music recording and playback.
May 1979, TDK’s first Metal cassette, MA-R, is released
The arrival of MA Metal tape and improvements to existing tapes
MA-R for Metal Position, revision I, appeared in May 1979. The aim was innovation in both tape performance and shell construction. The RS mechanism had a three-layer structure, sandwiching a precision die-cast frame between special plastic plates. Substantial weight and the combined action of the materials were believed to improve sound effectively. It was a substantial piece of work, in a sense embodying the ideal cassette: the shell is part of the deck. Deck manufacturers reportedly competed to use MA-R in product advertising photographs, impressed by both its performance and its appearance. MA-R was later renamed MA-XG. In July, the standard, mass-market, inexpensive MA Metal tape appeared. The tape itself was the same, but its shell was plastic.
November 1979 brought SA-X, the top High Position cassette with a double coating. It was based on SA, with AVILYN magnetic material applied in two layers.
The new AD was released in February 1981. Striped styling gave way to predominantly black packaging. Its flat sound response was presented as MUSIC REFERENCE AD. It was a tremendous hit: supply could not keep up, and apology advertisements were required. This was the impact of the black AD. Its campaign theme was American Sound Scene, featuring the Bee Gees and, in the following year’s second installment, Stevie Wonder: an illustrious lineup. MA-R revision II appeared in May. The new OD and new SA followed in August with new construction and styling.
The Normal tape AD-X appeared in January 1982. Positioned above AD, it took first place in tests by a German public institution, shaking the stronghold of BASF, Germany’s proud brand. TDK Europe’s support for a Rolling Stones tour and advertising collaborations with major overseas musicians such as Paul McCartney and Phil Collins also demonstrated their high regard for TDK cassettes.
The short-playing music tape PLAY TIME 8 appeared in March 1983. I heard there was resistance to selling it to ordinary users rather than professionals, but in practice even among the author’s acquaintances, many used it for singing and instrumental practice. MA-R revision III appeared that August, followed by AD-S (SPRENDER) in October, HX for High Position using Metal magnetic material in November, and other models.
The Normal tape AR was released in June 1984, followed by the new AD and new AD-S in August, the new SA in October, and others. AR stands for ACOUSTIC RESPONSE and sits above AD. It used new high-performance, highly crystalline NP (NON-PORE, meaning dense packing without voids) Ferric magnetic material. Powerful low and middle frequencies approaching Metal tape, together with low noise, were its defining characteristics. Repeated improvements kept it in production into the 1990s.
In 1985, April brought the new SA-X and new AR-X. October brought the new AR, SF and, for Metal, MA-X and MA-XG revision IV, among others. Cassette assembly began at the German factory in December.
AE for Normal appeared in February 1986, followed by the new AD in April. This version gained a large shell window and an entirely new design. Instead of the previous overseas artists, Keisuke Kuwata (桑田佳祐) of Southern All Stars became its advertising personality. With J-POP rising, the intention was reportedly for more approachable domestic performers to convey TDK cassettes’ good sound and convenience. Subsequent choices included Kahoru Kohiruimaki (小比類巻かほる) in 1988, Motoharu Sano (佐野元春) in 1992, Kome Kome Club (米米クラブ) in 1993 and Riona Hazuki (葉月里緒菜) in 1995. The new AR and new SF appeared in October.
The new AD and new MA were released in April 1988. A long-playing 110-minute version was also added. That year also brought the new MA-X, new AD-X, new AE, new AR, new SR and the High Position CUE.
Incidentally, cassette playing time, regardless of tape position, is generally designated C60, C90 and so forth: C is followed by the available recording time. The format began with C60, adding C90 in 1968, and eventually offered several dozen durations from C5 to C180. Greater duration means thinner tape, since the shell and magnetic material remain unchanged, reducing transport stability and durability. High-grade decks appearing around the 1970s used dual-capstan and similar arrangements for firm tape contact, requiring appropriate strength and precision. During the radio-cassette boom, conversely, primitive mechanisms sometimes chewed up or broke tapes, and such versions gradually fell out of use.
The CDing series, released in August 1989 for positions I, II and IV, perhaps expressed the intended recording task most directly in its name. Naturally, these cassettes targeted copying CDs. They answered the growth of CD-rental outlets and the associated demand. Sony and other manufacturers also introduced series with CD-style names. Numerous playing times and the choice of Normal, High Position and Metal brought these cassettes a measure of popularity. A C54 version of the new AD was added that year; as I recall, C54 had first appeared with the original AD. A recording-media factory was established in Luxembourg that August.
Variations on familiar cassettes and the end of magnetic tape
The new AD90 and new AR54 were released in February 1990, followed by MA-XG Fermo in March. MA-XG Fermo was the definitive, top-grade MA-series model. Besides the series’ first dual-layer application of Finavinx (ファイナビンクス), it had a complex five-part construction. No metal shell was used; instead it employed ceramics and black glass-fiber-reinforced resin. Even the screw fastening was unusual: from the sides rather than above. The Fermo name was used only in Japan; overseas it appeared as MA-XG III, second generation.
The new AR and new SA appeared in October 1991, the new SR in September 1993, and the new AR, new SA and DJ2 in October 1994.
In April 1995, AD1 for Normal Position was introduced specifically for music recording and playback: AD had simply been renamed. Initially called AD Type1, it presumably received the simpler, clearer designation because Normal = Type 1 was already common knowledge. The High Position AD Type2 likewise became AD2.
BEAM1 (Normal) appeared in March 1998 under the slogan Glowing, visible, powerful sound. This unusual variant used Light Charge, a light-storing mechanism that made the title readable even in darkness. MA-EX (EXtended) followed in September. This was effectively TDK’s final Metal tape and the last from a Japanese manufacturer. Besides some cost reduction from the earlier MA, it was the only model in the entire MA series manufactured and shipped in Thailand. MA production and shipments ended by September 1998, closing its roughly twenty-year history.
DISC JACK and the new CDing appeared in November 1999. DISC JACK packaging says DJ, which might suggest disc jockey, but actually abbreviates disc jack. Its slogans were Clear sound and Collecting CD singles in one recording.
NANA (High Position) appeared in 2001 exclusively for convenience-store sales. This fashionable cassette was sold only in those stores, not in ordinary electronics shops or other outlets. Yet people often dashed in for a cassette suddenly needed, making it perhaps the most typical cassette in that sense.
The TDK History Museum was built in Nikaho, Akita Prefecture, in December 2005. In April 2007, the TDK-brand recording-media sales business was transferred to America’s Imation. Shares in that company were acquired in December 2013.
In March 2014, TDK announced its withdrawal from all recording-media business. Its sixty-year magnetic-tape history had ended.
Lou Ottens of Philips, the cassette’s developer, died in March 2021 at the age of 94. Britain’s BBC reported cumulative cassette sales of 100 billion units. Incidentally, at the cassette’s peak in 1988, TDK held the world’s largest market share.
▼A cassette released after the TDK-brand recording-media sales business was sold to Imation. This model belongs to the very last period of the TDK brand.