Sony WM-FX290 / WM-FX290W PCB

The Sony WM-FX290 printed circuit board (PCB) is high quality, consisting of conventional and surface-mount device (SMD) components. The audio circuit uses the Toshiba TA417A9 audio IC, which is one of the best designed for the audio markets.

Radio Section

Here is the radio section of the PCB, and the component count is small due to the advanced ICs. There are two versions of this Walkman, the WM-FX290W can pick-up TV signals, and weather band channels. The main difference will be with the firmware and the resonators, whilst everything else remains identical.

TA417A9

The TA417A9 is an audio IC manufactured by the Toshiba Corporation. This IC operates on a single 1.5 V battery, and contains the preamplifiers for the audio head, and power amplifiers for driving the headphones.

It is interesting that the audio IC is smaller than the headphone socket.

Ferrite Rod

This is the ferrite coil for the radio function.

This Article Continues...