Rock Out With A Wrist-Strap DIY Mini Synthesizer @ Wired Design.

DIY electronic music makers, warm up your soldering irons: A pair of hardware hacking designers have created a miniature two-button, solar-powered synthesizer with a 3-D printed wrist-strap housing, and the full set of plans are posted online for you to make your own.

Most synthesizers take the form of piano keyboards, with multiple octaves of black and white keys and a batch of knobs that turn sine waves into a sawtooth among a million other audio tweaks. The product from Lucerne-based artists/designers Felix Bänteli and Roman Jurt is much, much simpler. It comprises a small plastic casing with a nob and a mini jack on either side of an ATtiny13 transistor, flanked by a piezo speaker and a tiny solar panel. That panel gives the device the ability to make and tweak sound — either privately through the headphones or publicly through the speaker — anywhere one desires.