This 80's circuit uses a microcontroller programmed to generate various songs. The circuit can serve as the basis for a modern design, for example using Arduino. The old circuit included a small audio amplifier.
This circuit for low frequencies (bass) was found in a Popular Electronics from the 90s. The...
New Low-Power PIC24 “GA7” Microcontroller Family Now Available CHANDLER, Ariz., Dec. 12, 2016 — The...
This excellent preamp for use with guitars was found in a 1986 documentation. The key on the TR2...