Astable 555 (CB21101E)

This 50% duty cycle configuration was found in a Popular Electronics from the 1990s. The operating frequency is given by C1.

Comparator with Transistors (CB6550E)
This circuit was obtained from a Philips documentation from 1968. The transistors can be replaced...
XR2206 sinusoidal generator with modified range (CB24497E)
The figure shows how to use the XR2206 to generate sinusoidal signals in a different way. The...
JFET Headphone Amplifier (CB25567E)
This headphone amplifier has good gain and high input impedance. The circuit is from Electronics Now and...