Here are a just few of the 30+ amplifier projects built by the Fall '16 Lick-Wilmerding Analog and Digital circuits class. Students mixed all kinds of materials and tools from the CNC cutting to 3D printing to found objects. All of the amplifiers use a class-D amplifier IC circuit at the heart, to which many students added extra features like tweeters, analog potentiometers, bluetooth connectivity, and audio responsive lights.