Type of connector: JVC J-Link
I needed an aux input for my old JVC LH70R but the official adapter was too expensive, so i do a little mod. I done some soldering on the PCB to get the AUX input out of PCB.
These are the pictures (it’s not a wonderful job but it work well :D)
2 useful link about pinout:
JVC LH70R Service Manual:
at the end of the page you should see this advice