Preamplifier stage (CB8934E)

This circuit is from a 90s Popular Electronics. It appears elsewhere on this site. Q1 can be any general purpose transistor.

Small Audio Amplifier (CB14736E)
This amplifier was found in a 1957 Rayrtheon documentation. The circuit can be fitted with a BC558...
Constant Speed Motor Control (CB24127E)
This circuit was obtained from the May 1971 issue of Radio Electronics magazine and is intended for...
Triggered Astable NOR Gate CMOS 2 (CB10729E)
Although it is a common configuration today, this circuit was taken from an old publication. The...