Adding USB or 3.5mm audio input to old boombox

[jure8479]

Hi,

For some time now I was thinking of adding a 3.5 mm female jack to an old Sony boombox (portable CD player). The model name is "Sony CFD-S47".
Not long ago I have opened it to replace the LCD backlight bulbs and a malfunctioning button (micro switch). Then the idea of adding an USB port for mp3 playback came to mind, but after considering the complexity of that project I decided to try adding a 3.5 mm female jack first.



How complicated is this (USB / 3.5 mm)? Has anyone added an USB port for mp3 playback to an old CD player?

 

[barry]

Add USB? Forget it. You'll something to convert the USB data to audio, and then insert that audio signal into the boombox signal path. Why not use the AUDIO output of your mp3 player into the boombox?

Without a schematic, I wouldn't attempt this project.Is there a LINE input on your boombox?

 

[jure8479]

Unfortunately, the boombox has no LINE input. I was considering connecting the input to the CD player (or cassette player) directly, in a way that when a CD is in the boombox you can play music from it and when there is no CD use the CD source as mp3 input.

As for the USB port, I was thinking of maybe programming a micro controller to decode the mp3 and then send the analogue audio to the speaker.