WM-F31

The WM-F31 is an affordable radio Walkman built directly from the WM-33 playback platform, adding an AM/FM stereo tuner while keeping the same low-cost mechanical foundation, three-band graphic equalizer, and two-AA power system. The body became slightly larger to accommodate the tuner hardware, but the basic logic of the machine remained unchanged: simple cassette playback with just enough extra functionality to broaden its usefulness. The radio integration stayed tidy and did not overwhelm the original chassis.

Here Sony was scaling radio downward into the budget end of the line without needing an entirely separate product philosophy. It was not a premium tuner machine, but a functional radio version of an already proven everyday platform.