TDK CASSETTE
From Synchro to TDK: the beginning of TDK Cassette
First-generation F: 1968
C60: 500 yen.
Second-generation F
C60: 500 yen.
First-generation TDK CASSETTE
C60: 700 yen.
TDK CASSETTE: explanatory notes
In 1968, TDK, then named Tokyo Denki Kagaku Kogyo Kabushiki Kaisha, changed its recording-tape brand from Synchro Tape to TDK Tape and its cassette brand from Synchro Cassette to TDK Cassette. The apparent aim was to unify the corporate name and improve the company’s image. TDK thus became the cassette brand name too, prominently displayed on its products thereafter.
Alongside the rebranding, a C90 priced at 1,000 yen joined the range. The same year brought an economical F version with a transparent shell in a cardboard box, 200 yen cheaper than the earlier plastic-cased version. These additions turned TDK Cassette into a series. C-30 and C-120 playing times were added around 1969, completing the early TDK Cassette lineup.
TDK CASSETTE LOW NOISE
The predecessor to D, later a long-running success
1971
C60: 800 yen.
A minor update to TDK CASSETTE. Packaging barely changed from the previous model, but LOW NOISE was added to the right side of the front. A few years later this model gave rise to D, which would enjoy long-lasting demand.
Synchro Cassette
TDK’s first cassette, where it all began
1966
C60: 700 yen.
This was the first cassette TDK offered to the general public, beginning in September 1966.
Japan’s cassette history began in 1965 with imports and sales from Philips of the Netherlands, the cassette’s developer. Japanese companies began domestic production the following year, 1966. TDK, previously a maker of open-reel tape, was also among the first to manufacture cassettes. Alongside demonstration tapes supplied to recorder manufacturers and OEM products, Synchro Cassette was its first cassette sold directly to ordinary users.
Synchro was then the brand name for TDK’s tapes. Since the open-reel product was called Synchro Tape, the cassette was apparently named Synchro Cassette.
At the shell’s upper right, TDK appeared modestly inside an oval, almost as a manufacturer’s identification.
At launch, only a C60 was available, priced at 700 yen.
SD
The world’s first music-recording cassette: Super Dynamic
SUPER DYNAMIC
First generation: 1968
C60: 850 yen.
The first generation appeared in 1968. Beyond high performance, it offered luxurious presentation: glossy, mirror-finished black tape, gold packaging and a plastic case with gold embossing.
Updated first generation: 1972
C60: 700 yen.
A minor first-generation update, changing the shell label design and price. Hi-Fi appeared on the packaging.
Second generation: 1972
C46: 500 yen.
The second generation was released in 1972. As part of TDK’s Dynamic Series, it adopted striped packaging. Its model color was blue.
SD: explanatory notes
SD is considered the world’s first cassette for recording music; the first generation was released in 1968.
Although cassettes were simple and convenient, format limitations, including low tape speed, limited their upper frequency response to 10 kHz. They were therefore initially considered unsuitable for high-quality music recording.
SD used ultrafine needle-shaped magnetic particles to extend frequency response, reduce noise and increase sensitivity. New binder and coating technologies prevented dropouts and signal-level fluctuations. A mirror-finished tape surface reduced noise. These and other improvements extended response across the human audible range of 20 Hz to 20 kHz and widened dynamic range. This innovative product demonstrated that cassettes were fully suitable for music recording.
After SD appeared, other companies released their own music tapes one after another, leading to the cassette’s flourishing as a music-recording medium.
ED
An exceptionally high-performance Normal cassette with jet-black magnetite tape
EXTRA DYNAMIC
First generation: 1973
C60: 800 yen.
The first generation was released in 1973. Its striped packaging used orange and gold. The black shell looked expensive, and the jet-black tape surface also suggested high sound quality. Priced the same as the chrome KR, this was an expensive cassette.
Second generation: 1977
C60: 800 yen.
A version with an improved shell, released in 1977. The same high-precision Precision cassette half sections used by SA and other models raised its grade. The C45 used a large 30 mm hub, further improving transport stability.
ED: explanatory notes
ED stands for Extra Dynamic. It went on sale in 1973 as the top model of TDK’s then-current Dynamic Series.
Its chief feature was magnetite as the magnetic material. Magnetite is a magnetic iron ore, a mineral with inherent magnetic properties that can be regarded as a natural magnetic material. It surpasses the usual gamma-hematite in coercivity and several other characteristics, but instability had previously prevented its use in tape coatings. TDK succeeded in stabilizing magnetite and became the first company to use it as ED’s magnetic material.
MOL, the maximum recording level, reached +4 dB at low and middle frequencies and +1.8 dB at high frequencies. Its capabilities exceeded chrome tape, then considered the best performer. Yet ED operated at ordinary Normal bias, making its exceptionally high performance available even on decks without chrome-tape support.
D
Inexpensive, convenient and good-sounding: an outstanding basic standard
DYNAMIC
First generation: 1972
C60: 400 yen.
The first generation appeared in 1972 as the basic Dynamic Series model. Warm orange and red stripes made a vivid impression. All versions came in plastic cases at a lower price than their predecessor. The model remained popular for a full seven years.
D: explanatory notes
This was the basic low-noise cassette in TDK’s lineup.
D stands for Dynamic. The first generation appeared when TDK reorganized its cassette range in 1972, introducing the striped Dynamic Series. D was the updated version of the previous TDK CASSETTE.
It used ordinary iron oxide, but SD technology and ultrafine particles raised sensitivity by 2 dB over its predecessor. New coating technology and a high-precision shell reduced dropouts and wow and flutter while improving durability. The advances over the earlier model were substantial. Although high-frequency extension fell short of SD, flat, balanced sound made D entirely suitable for music recording. It matched decks and recorders well and was a convenient all-purpose cassette.
A first-generation C60 in a plastic case also cost 400 yen, less than other cassettes in its class at the time. It offered excellent value for money.
The model was so common that one might ask whether anyone who used cassettes in the 1970s never tried one. It remained a practical standard cassette across four generations until the mid-1980s.
Second generation: 1979
C60: 400 yen.
The second generation was released in 1979 as a standard cassette for high-quality recording in a new era. New gamma-hematite-based High-Grained Ferric material was used. Increased coercivity greatly improved high-frequency performance. High-frequency sensitivity rose by 2.5-4 dB and MOL by 3 dB.
Third generation: 1981
C46: 350 yen.
The third generation arrived in 1981 with a completely different design. The Reliable Cassette mechanism improved transport stability. Its precision shell sections became black. Packaging was renewed while retaining the model’s orange and red colors.
Fourth generation: 1983
C46: 350 yen.
The fourth generation appeared in 1983. High-Grained Ferric particles were made still finer and their performance improved, raising high-frequency sensitivity and MOL. The shell used the reliable, durable RC mechanism. Raised marks at the lower right of the shell sections allowed sides A and B to be distinguished by touch.
Advertisement featuring first-generation D in the foreground:
You are surrounded by sound. That alone is enough to feel freedom of the soul. 24 hours a day, 365 days a year. May it always be so.