The WM-55 was unusual for two reasons, firstly it was available in vivid pink, an unusual colour for a Sony Walkman of the 1980s. Secondly a radio unit in the shape of a cassette (model CTP-1A) was included, this was inserted in place of the tape cassette and allowed the reception of programmes on both the AM and FM bands, in stereo on FM if desired. Other manufacturers (e.g. Aiwa, Sanyo and Toshiba) frequently offered radio modules of this type but Sony more usually miniaturised the radio circuit to such an extent that it could fit somewhere inside the normal Walkman case, such as inside the cassette door (e.g. WM-F10, WM-F107). Text copyright © Walkman Central. Unauthorised reproduction prohibited.
The CTP-1A module had its tuning and waveband controls placed so that they were accessible through a slot in the side of the WM-55 main unit, the tuning scale was visible through the tape viewing window and the unit was activated by pressing the play button. The interconnections that were made as well as passing power and signals also stopped the motor running, conserving battery power. Text copyright © Walkman Central. Unauthorised reproduction prohibited.
The WM-55 was well made and finely finished, the cassette door even included a small catch operated by a slide switch to prevent it falling open, another unusual feature. The mechanism, which used a metal chassis and included switchable auto reverse (sides 1 and 2/continuous play), was shared with models such as the WM-75. Also in common with the WM-75 were Dolby B noise reduction and normal/chrome/metal tape compatibility. Text copyright © Walkman Central. Unauthorised reproduction prohibited.