This circuit was found in a Radio Electronics from April 1990. The circuit has 5 equalization bands given by the capacitors used.
In the figure we have an amplification stage with FET in the source follower configuration. The circuit is...
This circuit is from an old American documentation from the 70s. Transistor 2N3904 can be replaced by...
This nonlinear gain circuit was found in a 1965 Electronic Design. The configuration can be used...