Středa 17. Červen 2015, 16:15 hod.

This type of radio unit was present in Renault Megane around 1998. It is standard radio/cassete unit with opportunity of CD changer connection, but no possibility of easy AUX connection. However, you can have AUX input on Radiosat 6010 and it works on mine. But I must warn you, you need good skills with soldering iron and knowledge of electronics. Don’t ask for my advice, if you break something.

P6172748_res

Theoretical background

– The main object of interest is intergated circuit TDA7342. If you look into the datasheet (google for it), you will find, that it is some kind of two-ICs-in-one. The first part is responsible for selecting one of the inputs, based on data send from main microchip. Selected input is send to pin 3 (right channel) and pin 16 (left channel). And then immediately routed back via filtering capacitor to pin 2 and pin 15 to the second part of IC responsible for signal attenuation (volume, balance, treble, bass, etc.).

– There are special kind of 3.5 mm audio jack sockets with double switch. If you insert this jack socket (see picture below) in between pins 3->2 and pins 16->15, two situations can occur. If no jack plug is inserted, radio/cassete/cd signal is routed normally. If you insert jack plug into socket, this path is interrupted and signal from jack plug is routed to output.

dpdt
Source: ges.cz

How to make a connection?

– Unit part. Desolder capacitor beetween TDA7342 pins 3->2 and 16->15. As it is electrolytic type, don’t forget to make a mark, where +/- side is (on mine unit pin 3 and 16 is +, pin 2 and 15 is -). Get a shielded cable with 4 wires (see picture below for example). Solder white cable to + leg of capacitor, solder purple cable to hole leading to pin 3 on TDA7342 and solder – leg of capacitor back to hole leading to pin 2. Similarly light blue to + leg of capacitor, dark blue to hole leading to pin 16 and – leg of capacitor to hole leading to pin 15. Solder shielding wire to PCB ground.

sykfy2
Source: ges.cz

– Jack socket part. Solder white cable to pin 2, purple to pin 3, light blue to pin 5, dark blue to pin 4, shielding wire to pin 1.

– Check once again. You must have this connection: TDA7342 pin 3 -> purple wire -> jack pin 3 -> jack pin 2 ->white wire -> capacitor -> TDA7342 pin 2 and TDA7342 pin 16 -> dark blue wire -> jack pin 4 -> jack pin 5 ->light blue wire -> capacitor -> TDA7342 pin 15.

– You can put your jack socket wherever you want, i used CODE button as it is dummy one.

Enjoy!