Recent trends are to move the plugs in the back of the computer, up to the front for easy access. This tutorial will be about moving a headphone jack from the back of the computer, onto the keyboard. If you use more than one headphone like I do, you will see the beauty in this mod.
This is 24 AWG audio wire. Inside that, are 3 wires. There is a white one, a blue one and a loose one that wraps around throughout the inside. One is the left speaker, one is the right speaker, and the loose one is the ground. Strip down all the wires as shown above on both sides of the wire. One end will plug in the back of the computer, the other end will be placed inside the keyboard.
This end will plug into the sound card. Make sure you purchase one that says stereo, and that it comes apart like shown. Inside the jack, there are 2 prongs, and a long shaft. One prong is the left speaker, the other is the right speaker. It doesn't matter which wire you use, pick one. To attach it, you can either solder it, or twist it and use heatshrink like I did.
Take the ground wire and leave it loose inside. The catch is to allow it to wrap around inside. If, at the end, you aren't getting stereo sound, I'll guarantee the problem is right here. I have no idea what it is supposed to be touching, but I find playing with this ground wire is where there problem usually lies.
On the left, the jack is now finished, and ready to be placed in the soundcard. On the right, is the part going inside the keyboard. This acts the same way, were one is left, one is right and the other is the ground. The left and right go in the back, and the ground goes on the loose connector on the side. I chose this type of jack because it's the smallest one. Once you get inside the keyboard, you will see how tight it is in there.
Open up the keyboard by taking out all the screws. If you have a new keyboard, this isn't a problem. If you have one from a 486 computer, I would not suggest you try this. Inside old boards are over 100 springs which will shoot out everywhere (as I once found out).
Take a drill bit, and cut out the hole for the jack, as well as a place for the cable to come out of. Then run the cable through and close up the keyboard.
That's about all there is too this mod. The trickiest part seems to be getting it through in stereo, and not mono. Pop in an MP3 or something and fiddle with it until you get it.