We found this 6-tube amplifier in a 1947 publication. It is a Public Address amplifier with excellent performance using triodes on the output.
This circuit can serve as a basis for a digital mixer or simply for a noiseless switch of audio...
This traditional mixer configuration with a high input impedance was found in a 90’s Popular...
This medium wave radio works with any general purpose NPN transistor. The diode must be made of...