WM-EX508

The WM-EX508 is a flexible midrange EX-series cassette player whose most unusual feature was its reversible battery-door system, allowing it to run either on a gumstick cell or standard AA power depending on which configuration was attached. Alongside that it offers auto-reverse playback, Dolby B noise reduction, Mega Bass, anti-rolling support, and Sony's automatic volume limiting system in a compact body built to stay portable under different power situations. The playback side remained familiar, but the power system gave it a practical edge.

That battery flexibility is the real story here. The EX508 is a machine designed around real-world inconvenience instead of around showroom differentiation. It is a very good example of Sony was solving a compact portable-audio problem in a way that made the object genuinely easier to live with.