This toy transistorized organ was found in the May 1970 issue of Radio Electronics magazine. The trimpots are adjusted to the musical notes according to the key.
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...
This voltage level-triggered circuit was found in a 1969 Ferranti English documentation. Modern...
Found in a 90s General Electric documentation, this circuit has a drain current of just 1.5 uA....