Amplifier with the 6FS5 (T393E)

This amplifier stage with the 6SF5 triode valve was found in a book with modern tube designs. The circuit has a gain of -47 times.

Microphone Booster (CB923E)
This circuit was obtained in a 1980 edition of Elementary Electronics a magazine that no longer...
12,5W Amplifier with the741 (CB4023E)
This circuit is from the 1990 Motorola Data Databook. The circuit can be implemented with...
Varicap Frequency doubler with (CB4107E)
We find this circuit in American documentation from the 1980s. It consists of a frequency folder...