WM-30

The WM-30 was an ultra-compact cassette Walkman from 1984 that refined the stretchable design introduced by the earlier WM-10, using a brushed metal case and upright layout that kept its footprint unusually close to that of a cassette itself. Powered by a single AA battery, it paired Dolby B noise reduction with a manual tape selector and a sliding chassis that expanded only when needed for cassette loading. The whole machine was built around the idea of making full stereo cassette playback feel improbably small.

Where the WM-10 had introduced the expandable format almost as a technical statement, the WM-30 feels more like Sony settling into that idea and making it usable at scale. It was aimed at people who wanted a Walkman that disappeared into a pocket or belt pouch without feeling flimsy or stripped down. More than a radical departure, it reads like the moment the super-compact branch started becoming a real part of the lineup rather than a clever side experiment.