Found in Radio Electronics magazine from 1959, this high-fidelity amplifier has 15 W of power. Power supply was not provided.
This oscillator from a 1970 documentation uses an operational amplifier that is no longer common on...
This circuit, with a 12 V input, was found in a Popular Electronics from the 1990s. Information is given...
This circuit is from an old publication of the 70's. It can be implemented with modern transistors like the...