He’s packed the entire device (called the Drum8 Vintage) into a single ATtiny84 14-pin DIP package ... [Jan] is offering the chip itself for $20, and has made a limited edition version that ...

Once the flat metal surface is exposed, the chip is placed in a socket, and a new pin is cut from the leg of a TO-220 power device. This is carefully bent over, inserted in the socket, and ...