WM-EX631

The WM-EX631 is a slim late-period EX-series playback Walkman built around a standing aluminum body that kept the machine compact, rigid, and easy to carry in one hand. It offers auto-reverse playback, automatic tape selection, Automatic Music Sensor search, blank skip, and Sony's familiar late-era sound processing through Mega Bass plus Groove and Revitalizer modes, all controlled through a wired remote and rechargeable battery system with a dedicated charging cradle. One of its more unusual additions was a variable tape-speed control dial, allowing playback to be slowed or adjusted for spoken-word listening, transcription, or language study.

This model shows the cassette Walkman no longer being shaped purely around music. By 2002, Sony was still refining playback machines, but the refinements had shifted toward practical use habits that survived longer than the mainstream tape market itself. The EX631 is a machine for people still actively using cassette as a tool, more than as a format.