This circuit for multiple sound inputs was found in a Radio Electronics from January 1992. It consists of a Bargraph connected to a multi-input mixer.
In this application we use an additional input circuit to enable logical command with switches, sensors...
In the figure we have the basic configuration of an operational amplifier for audio signals. The...
The MC33064 can also be used on this circuit of Motorola's 1993 Linear Interface ICs. The circuit...