High gain amplifier stage (CB20561E)

This audio amplifier stage was found in a 1963 publication. The circuit was designed to use germanium transistors. The headphone is 70-ohm.

Timer (CB5978E)
In the figure we have a simple timer with two voltage comparators of the four of an LM339. The...
Output stage with the AC117 (CB4278E)
This step is also suitable for the AC188k and SK3004 transistors and was found in a 1980s...
Darlington Power Switch (CB993E)
This circuit was found in an old publication about transistors. The circuit can be used to drive...