I made a simple instrument using a single string and pickup mic. Here are the steps:
Solder the wires to the appropriate pin on the headphone jack. Generally, the innermost pin is hot and the outer is ground.
For the digital component of this project, I used the following equipment: Tapco Mixer 50, Stereo RCA Cable (with 1/4″ RCA adapters), and two Yamaha speakers. An elaborate setup for a “simple instrument,” but I learned a lot along the way.
Here are some videos I shot of the sounds it makes:
[gn_media url="http://www.youtube.com/watch?v=SwVpi6VCW1I&feature=youtu.be" width="600" height="400"]
[gn_media url="http://www.youtube.com/watch?v=TDR3CgEF6SQ&feature=youtu.be" width="600" height="400"]