This low-noise, low-drift amplifier was found in a 90's EDN. It can be implemented with modern equivalent operational amplifiers. The font must be symmetrical.
This circuit was found in a 1987 edition of the United States' Hands-On Electronics magazine. The...
This amplifier circuit is from a 1952 documentation. The frequency of the amplifier signal depends on...
Found in Popular Electronics from the 1980s, this circuit can use more modern transistors such as...