1989 WM-506
The WM-506 is a playback-only Walkman equipped with an automatic inversion function.
1988
WM-505
The WM-505 is a playback-only Walkman with an automatic inversion function. It features Dolby B and is compatible with AA batteries and gum-type rechargeable batteries. It is an early high-performance model that combines automatic inversion and noise reduction functions.
Sony experimented with cable-free playback in the WM-505, pairing a compact cassette body with a short-range wireless audio system. It used an amorphous playback head, Dolby B noise reduction, Auto Reverse, Mega Bass, and an anti-rolling mechanism to keep the transport steady during movement.
The gumstick cell sat inside the enclosure, and the layout followed the late-eighties push toward a thin, symmetrical form with straightforward controls. The wireless system defined the model.
The WM-505 sent audio through a proprietary analog radio link to cordless headphones powered by their own gumstick battery. Within a limited range, the setup allowed cassette playback without a physical cable between the player and the listener.
The design carried practical limits. The radio link performed best over short distances, and interference or crowded environments could introduce brief dropouts.
See also WM-701C
