This is the first of my weekly PCB challenge projects, an electric piano soldering kit. It was based on  drj113's Stylophone design, with a couple of extra features I added, including; 

  • larger, louder speaker
  • toggle between the onboard speaker and a 3.5mm audio jack output
  • modified resistor chain that uses more common values
  • a new piano key layout designed in Fusion 360
  • A removable stylus with a banana jack