With this circuit you can produce the sound effect passing from one channel to another. The circuit is from Mullard documentation from the 1960s. The transistors may be the BC548.
This circuit was found in a National Semiconductor manual from the 1970s, appearing in articles and on...
Found in 1965s General Electric documentation, this circuit is intended for the control of servos...
We found in this American documentation this circuit for activating common cathode displays. In it we...