This is slightly off topic but can still fall under the realm of hardware hacking.







Ok to make a contact microphone you need a piezo electric disc, and a 1/8 plug, and some wire. It's best to have a piezo with wires, otherwise you need to solder one to the crystal and one to the metal. Attach those wires to the plug, and wallah a contact mic. Here are the pics and the video above.