Sony WM-2055

The WM-2055 is a stereo cassette player manufactured by the Sony Corporation in Japan. It has the MT-WM2051-43 tape transport mechanism which was a new introduction at that time. The WM-2055 was similar to the WM-F2061 and both had the same tape transport mechanism; however the latter model had an AM/FM radio tuner. The WM-2051 (available in 1990) was also a similar model but much more basic and lacked the Mega Bass switch and slider controls. These are all very basic players with a plastic cabinet case, and were mass produced. The unit shown in this multi-page article has the following features.

• Auto reverse with controls
• Dolby B noise reduction
• Normal and CrO2/Metal selector
• Mega Bass
• High and low frequency control sliders
• 3-V DC power socket
• 11-hours operation with Sony AM3 (N) batteries

Review

The mechanical and electronic engineering was fairly reliable and well designed for the time. The tape transport mechanism (TTM) is plastic, and contains a plethora of plastic cogwheels. The pushbutton mechanism is plastic too and very delicate.

The chipset was very common for that era and used by many other manufacturers too. The LA4581 is a preamplifier and power amplifier IC for 3 V stereo systems, and manufactured by the Sanyo Corporation. This was a very popular IC used in many other Walkman type stereo cassette players of that time, and the sound quality is particularly good providing one uses a high quality pair of headphones. The NJM2063 is a Dolby B type noise reduction processor manufactured by the New Japan Radio Corporation. An advantage of having a separate Dolby IC was that it enabled Sony to offer other cheaper models in the series without the Dolby functionality. The MM1038F is a speed control servo IC for DC motors and manufactured by the Mitsumi Corporation. It was a low-power device suited for cassette players with auto-reverse, and especially in designs where voltage drop occurs when the motor reverses.

The drive belt is fairly straightforward to replace, however the greatest problem will be removing the back cover secured by plastic claws. Remember that in addition to the claws around the edges there are some accessed through the cassette compartment and they will need unlocking too. The following pages of this article have photographs of the back cover which may help locate the claws.

Price/eBay

This is a very basic early unit that Walkman collectors may like to own especially for sentimental reasons. It sometimes comes up for sale, and a unit in mint condition together with its original packaging and headphones could fetch a very small tidy sum for the seller. As a buyer, remember that this is a basic early unit and there were much more advanced units in the series that came out later. In the following pages of this multi-page article you can see the inside view and photographs taken when I changed the drive belt.

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