This circuit was found in the April 1993 Electronics Now magazine. With it, it is possible to control the gain of an operational circuit with a JFET.
The integrated circuit used in this 1987 project is not very common these days. However, if found...
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...
This amplifying stage is found in several circuits on our website. The coils depend on the...