Found in documentation two years 80, this toy instrument uses an integrated circuit little commonly. As notes are given the values of key series resistors on the keyboard.
This circuit is from 2001 documentation, serving to multiplex stereo signals for FM transmitters. The...
This circuit reverses the signal if both positive and negative. We found it in an American...
Found in a publication by Gernsback from 1960, this circuit makes use of germanium transistors of the time....