This circuit was found in a Radio Electronics from April 1990. The circuit has 5 equalization bands given by the capacitors used.
In this circuit, from a 1977 publication, we have the traditional version of a filter tuned to 1...
We find this circuit in an American 1980s documentation. Modern equivalent integrated circuits can be...
Found in an old Popular Electronics this circuit can also be adapted to be used as a shield. In...