This nonlinear gain circuit was found in a 1965 Electronic Design. The configuration can be used as a basis for modern designs with equivalent transistors.
The diodes of this circuit are general-purpose, and the base resistors are typically between 2k2...
This circuit was found in the February 1981 issue of Radio Electronics magazine. The circuit uses...
The operational amplifier used in this circuit is no longer very common, but the configuration can be adapted...