This circuit can work with almost any JFET. The circuit is from an Electronics Now from April 1993. It is powered by a 12 V battery, but can also be powered by 9 V.
This circuit was found in a 1982 Maplin magazine (England Component Store). The circuit has...
This is the conventional version of capacitance multiplier with operational amplifier that appears in...
This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are...