The “ace” of HF, introduced as Sony’s highest-grade Normal cassette.
Normal Position. Since 1978.
First generation, 1978
46 minutes - ¥550 / 60 minutes - ¥650 / 90 minutes - ¥950.
The packaging and cassette shared the design of “DUAD” and other models, but in a different color: this model was blue. The shell had wide, rectangular windows around the hubs and was embossed over its entire surface. The plastic case was made entirely of transparent parts.
Second generation, 1983
46 minutes - ¥500 / 60 minutes - ¥650 / 90 minutes - ¥950.
The wrapping and cassette label acquired a shiny metallic finish. The magnetic material used newly developed ultrafine Single Crystal Gamma particles. Applying them with high dispersion, high density and a high degree of orientation further improved high-frequency characteristics and reduced noise.
Explanatory Note
The original “AHF” was released in 1978 as a higher-ranking Normal-type cassette for music, substantially improving on the long-selling, high-grade “HF.”
Its magnetic material was the commonly used iron oxide “gamma hematite,” but crystallized at high density after reducing the pores characteristic of this material to an extreme minimum. Making the particles ultrafine and improving their acicular aspect ratio also improved characteristics such as residual flux density and coercivity distribution. This extended the high-frequency range while retaining the rich midrange and bass characteristic of Normal tapes, achieving a wide dynamic range.
The cassette used the newly developed DP mechanism (Dual Protection Mechanism). A “parallel-grooved sheet” preventing irregular tape winding, a “stepped hub” with ribs on its inner and outer rims, and a “high-precision shell” stabilized tape running and suppressed modulation noise caused by poor tape transport.
Instead of cellophane packaging, it used wrapping with the product name and explanations printed in color.