Audio multiplexer with integrated amplifier project by Matt Winslow, built as a capstone project for his masters in EE:
This project is to act as a central hub for switching between audio sources and listening devices. Multiple audio sources can include a phone, computer, TV, etc. The listening devices can include different sets of speakers, headphones, etc. This project aims at reducing the hassle of unplugging and reconfiguring the desired audio source and listening device to just a button press. There is also an integrated volume control knob on the audio mux to conveniently change the gain in the same location as the buttons.
Project info at Winslomb blog.
Check out the video after the break.