Audio amplifier 741 (CB20478E)

This low power audio amplifier was found at 1992s Popular Electronics. Transistors are general purpose common types.

CB20478E

Common Collector Stage (CB4937E)
This is a typical common collector amplifier step configuration. The transistor can be used...
Variable Zener Diode (CB5875E)
This circuit was found in old documentation, but the transistor may be the modern equivalent BC547....
Oscillator with frequency triplicator (CB4052E)
The oscillator of this circuit operates around 8 MHz, but the output will be at a frequency three times...