This circuit was found in an American publication from 1968. The transistors are from the time, but it can be made from modern transistors.
This circuit is based on an uncommon Texas component today, as found in an American 1980s...
This circuit that generates a special sound was found in a Popular Electronics from the 90s. The...
This circuit uses a LM3900 Norton amplifier and a 2.7 V zener diode to supply a current of 1 mA to...