WM-R55

The WM-R55 is a portable cassette recorder Walkman that stood out for including a built-in mono speaker alongside switchable auto-reverse, Dolby B noise reduction, and line-input recording. Powered by two AA batteries, it also includes a mechanical tape counter and optional compatibility with Sony's cassette-shaped tuner pack, giving it more flexibility than most recording-capable Walkman models of its size. The metal-frame body and carrying case reinforce its role as a practical, multi-purpose player rather than a specialist recorder.

This model occupied an unusually broad middle ground in the lineup, useful both as a personal stereo and as a compact self-contained recorder that does not always require headphones. That made it appealing to users who wanted something functional and adaptable rather than especially refined or professional. The R55 is a good example of how many directions Sony was exploring at once once the basic Walkman formula had matured.