Voltage reference (CB20820E)

This circuit was found in documentation from the 1980s. The circuit can be designed based on modern components.

Headphone Amplifier (CB4386E)
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...
Variable gain operational amplifier (CB8068E)
This circuit is from an Electronics Now from the 90s. It applies to almost any operational...
1 kHz Oscillator (CB1410E)
This circuit makes use of germanium transistor, but can be mounted with a silicon transistor like...