Found in a 1967 Electronics World, this circuit uses unusual components today. The transformer has a high impedance primary.
This circuit is from an old Japanese magazine from 1960. The circuit uses germanium transistors from the...
This is the factory setting (National Semiconductor) of the TDA2006 as an audio amplifier. The...
This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The...