This 4-channel mixer amplifier was found in an American publication from 1947. The circuit uses counterphase output tubes and a transformer power source.
In the figure we show a widely used configuration for the CA3140. The power of this circuit can be...
The circuit shown was found in a Japanese publication from the 1960s. Transistors can be...
This circuit was obtained in a Popular Electronics of the 90s. The circuit can be assembled with...