We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach logic using integrated circuits of the TTL family. The 5 V power supply is included.
Using a CA3130 operational amplifier, this circuit was found in an English publication from 1977....
The purpose of this circuit is to transmit the signal from a guitar pickup to an FM receiver...
This direct coupled circuit operates in class AB with good gain. The circuit is powered by 12 V....