STEREO MICROPHONE JACK WIRING

How to Hack a Headphone Jack - circuitbasics
TRS Audio Jack. TRS audio plugs are found on standard stereo headphones that don’t have a microphone. After you cut into the cable, you’ll probably find one of three common ways these can be wired: Copper wire ground sheath wrapped around two insulated audio signal wires.
How to Wire a 3 Stereo Audio Plug | It Still Works
The 3 stereo audio plug is the standard jack for MP3 players and other portable audio devices. This mini-plug was developed because a lot of modern equipment cannot accommodate standard 1/4-inch jacks. The small size of the 3 plug makes wiring one a bit difficult, but with practice and the right soldering