Hacking my boombox

  I have couple of small projects lined up, the first of which was to convert the cassette input into an AUX (auxiliary) input. The boombox in question is SONY CFD-S33. The function button on it controlled the sound from either one of the three inputs which were Tape / CD / Radio. I have stopped playing cassettes for quite some time and I needed to use it outdoors. Unfortunately this year, while using it for some outdoor shoots, I realized that I cannot rely on it's CD playing capabilities either. So either i needed to buy a new boombox or add an AUX input to play from any device which has 3.5mm audio output.
  For couple of reasons I went with second option. This instructables page helped me get started. The only thing I needed to buy was 3-conductor phone jack (RadioShack part #274-0249). Accessing the screws to open up the box was a herculean job though. In the end I opened it up and connected the 3 wires coming from the phono input. This boombox also has TA20168N chip for radio and tape head pre-amplification. I tapped on the output side of the chip as follows:

• Right channel -> red wire -> pin 18
• Left channel -> white wire -> pin 20
• Ground -> black wire -> pin 7

Turned out that this setup taps into the radio input instead of tapping into the cassette input. So now I have to set the function to Radio input and if the AUX input is unplugged then I can hear the radio but if it is plugged then I can hear whatever is being fed into the aux input. Now need to test it's performance in the heat outdoors.