Sony WM-FX113

The WM-FX113 was a stereo AM/FM radio cassette player Walkman manufactured by the Sony Corporation in approximately 1995 and assembled in Malaysia. It has the MF-WMFX103-48 tape transport mechanism that was also used on the WM-FX101. This is a basic player with the following features and specifications.

• AM/FM Radio with manual tuning
• Mega Bass selector switch
• Anti-Rolling Mechanism
• FF and REW tape controls
• Automatic Volume Limiter System (AVLS) with three settings (OFF, 1, and 2)
• Normal, CR02/Metal tape selector
• 3 V DC input socket (centre pin positive)
• Detachable belt clip
• Dimension: 93.9 mm × 118.5 mm × 35.7 mm
• Mass: 205 g (including batteries)

Review

This is a lovely basic player with simple functions that may appeal to the Walkman collector. This unit does not have Dolby or auto-reverse, but has other charms such as old-fashioned manual radio tuning by way of a variable capacitor. The chipset was fairly advanced and efficient for its time and with a pair of Sony Alkaline AM3 (N) batteries one could expect 8-hours of cassette operation, and 30-hours of radio use.

Apart from metal springs, the tape transport mechanism (TTM) uses virtually no metal parts and consists of a plethora of plastic cogwheels. The pushbutton assembly also consists of mainly plastic parts and has a soft feel when pressing any of the buttons. The TTM chassis is very small and light plastic fabrication and uses the PCB for additional rigidity. In this design, a small DC motor (H3B12Y) drives a pair of flywheels via a single belt. This design does not have auto-reverse hence the second flywheel has a shorter capstan spindle. Hence, my impression was that this TTM was a simpler cut-down version of another design that had auto-reverse. The motor is controlled by a basic servo amp IC MM1038BFF-T1, and notice how there is no system controller in this design. Other integrated circuits include:

• TA8122AF Single chip radio solution
• LA4582CM-TLM Pre and power amp

The sound quality and radio reception are excellent, but it all depends upon the headphones you decided to use with it. Remember that the headphone cord also doubles as aerial for the radio tuner. Changing the drive belt in this unit was fairly straightforward, as the flywheels and pulleys are easily accessible. The most difficult part will be to remove the back cover which is secured by plenty of plastic claws. In the following pages of this article there is a photograph showing the back panel, which may help.

Price/eBay

It’s a lovely unit that sometimes comes up for sale, but it is worth keeping in mind that this is a very basic design, with interesting electronic and mechanical engineering. I would anticipate a broken unit to need a new drive belt, but with the plastic mechanism and cogwheels inside it, there might be a few out there that need more extensive repair. A unit in mint condition with its original box with packaging would be highly collectable for the Walkman collector.

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