Stereo preamplifier (CB8510E)

Found in a 90s Popular Electronics, this circuit is based on a uA739, an unusual component today.

Operational Astable (CB14826E)
This is the conventional configuration of an astable multivibrator with operational, found in a...
Triple 5 V Numitron power supply (CB8673E)
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
Telephone Equipment Regulator (CB6030E)
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...