This circuit is from the 70s. The integrated circuit used is not common today and the supply is made with a voltage found in televisions of the time, where it was used.
This stage was used in old audio ampliiers and radios from the 1950s and 1960s. It uses one of the...
Found in a 90s R-E Experimenter Handbook, this amplifier uses an integrated circuit from that...
We find this circuit in an American 1980s documentation. The unijunction transistor may be the...