We found this circuit in a 70s Electronic Design documentation. The circuit uses general-purpose transistors from the time. Linearity is better than 0.25%.
In the figure we show another interesting application for integrated circuit 4001. This circuit...
This audibility or loudness control for sound equipment is from 1992 documentation. The circuit uses...
This circuit was found in an application note of the LTC1164 from Linear Technology of the 1990s....