This high input impedance tone control circuit was found in American documentation from the 1980s. Equivalent operational amplifiers and FTEs can be used.
Found in documentation from the 1980s, this circuit can generate signals in a range that reaches a few...
Found in a 1967 publication by General Electric, this control is intended for motors up to 2 A...
This circuit was found in a 90s Popular Electronics. The circuit uses components from that time,...