“Crystal Set / Self Test” executes an artistic test on the physical centerpiece of contemporary digital devices. The basic raw materials of our surrounding information technology are semiconducting crystals such as silicon, galena, germanium or silicon carbide, which, thanks to today’s advanced microtechnology and extremely sophisticated procedures, are processed into transistors or integrated circuits (IC). Crystal Set is an apparatus based on a raw silicon carbide specimen. 64 iron needles are attached to the surface of the specimen and build a semiconducting transition (diode) at the contact point. Silicon carbide has two additional qualities: it emmits light at the contact point (LED) and produces audible signals (piezoelectric effect). A programm investigates the logical structure of the crystal. It applies different electronic pattern to the contacts based on an analysis of current flow, resistance and response times in the specimen. By doing this it is inspecting its behaviour in a closed feedback loop. As a result it generates raw and untamed signals visible and audible to the observer.