A high-end Normal cassette equipped with a “ceramic tape guide.”
Normal. Since 1984.
First Generation, 1984
46 minutes - ¥600 / 60 minutes - ¥800 / 90 minutes - ¥1150.
The packaging used blue tones as its model color, as on “HF-ES.” The cassette itself was white, suggesting ceramics, but its shell was plastic. The ceramic component was visible only around the positioning holes and could hardly be seen from outside. Even so, picking up the cassette revealed a substantial weight that made its presence tangible. The tape was a powerful type with a residual flux density of 1750 gauss.
Explanatory Note
“HF-PRO” was a version of “HF-ES” with an upgraded internal mechanism. It used “ceramics,” then attracting attention as a new material, in part of the cassette’s construction.
It was used in a part inside the cassette called the “tape guide,” where the tape rubbed against the cassette-shell components: inside the thickened part of the shell into which the deck’s head entered. To suppress the minute vibrations generated here at their source, a separate molded component made from the ceramic composite “ファインセラミックコンポジット材 (Fine Ceramic Composite)” was used, combining ceramics with a special resin. Its high elastic modulus, low coefficient of friction and sound-absorbing properties absorbed and damped vibrations, substantially reducing modulation noise.
The tape used was equivalent to that of “HF-ES,” the highest-performance Normal cassette. In other words, this was Sony’s high-end Normal cassette combining the finest tape with the most powerful mechanism. Comparing it by ear with “HF-ES” made it possible to appreciate the effect of the “ceramic tape guide.”
Second Generation, 1986
46 minutes - ¥550 / 54 minutes - ¥600 / 60 minutes - ¥700 / 80 minutes - ¥900 / 90 minutes - ¥1000.
The packaging received a new design. High-density packing of the magnetic material using SDC (Super Dispersion Control) technology raised high-frequency MOL by 0.5 dB. Like the original model, it used a white shell with an extra-wide window. Prices were lowered slightly, and 54- and 80-minute versions were added.
Third Generation, 1988
46 minutes - ¥600 / 54 minutes - ¥650 / 60 minutes - ¥700 / 80 minutes - ¥850 / 90 minutes - ¥900.
Prices were revised later.
Not only did the package design change, but the cassette itself also received a black shell, substantially altering its appearance. Alongside the “ceramic tape guide,” it adopted an IS (Infinity Shape) shell with reinforcing ribs that increased the shell’s rigidity. The window became a horizontally elongated slit.
Fourth Generation, 1990
46 minutes - ¥580 / 54 minutes - ¥630 / 60 minutes - ¥680 / 74 minutes - ¥770 / 90 minutes - ¥880.
A minor-change version of the third generation, with a revised package design. Like its predecessor, it used the cobalt-based Super Cobalt Crystal magnetic material, with a residual flux density of 1800 gauss. Combining an IS shell with a “ceramic tape guide,” it was Sony’s most powerful Normal cassette.