Having the ability to properly wire stereo jacks can be an asset to anyone who works with audio devices. Stereo jacks come in a variety of sizes, depending on their use. Large stereo jacks are usually used for large sound equipment, such as electric guitars and PA systems. Smaller jacks connect headphones and other devices to iPods, cell phones and MP3 players.
Strip about half an inch of insulation from the audio wire. Use a pair of wire strippers to remove the insulation, being careful not to damage the wires inside.
Separate the four wires. There should be a black wire, a red wire and two uncoated wires. Twist the two exposed wires together to make a total of three wires.
Use the wire strippers to remove about a quarter-inch of insulation from the two coloured wires.
Unscrew the stereo-jack housing using a small screwdriver. The main part of the jack has three small screws. The top screw is the "ground"; the other two are for the left and right audio connections.
Unscrew each screw slightly. Loosen just enough of the screw to allow you to insert the audio wires between the screw and the fixture.
Attach the uninsulated wires that you previously twisted together under the top screwhead and tighten the screw firmly. Tug on the wires to ensure the connection is strong.
Repeat the process for the two remaining coloured wires. The screw that the coloured wires connect to can be interchangeable. If your stereo jack is labelled with (+) and (--), then the red wire goes to the (+) screw.
Slip the body of the jack cover up to the jack plug and screw it in tightly.