This circuit was found in an 80s documentation. The integrated circuit used is from that time, being a component that is difficult to obtain today.
This 2000 circuit can be used to match the low impedance of a microphone to the high input...
Figure Bellow shows how to interface CMOS circuitos with TTL using the 4049 or 4050 IC. The power...
The basis of this circuit is a National Semiconductor operational amplifier that functions as a...