The cut-off frequency of the circuit shown in the figure is 750 Hz, with the components used. The circuit applies to almost any operational amplifier and the power supply must be symmetrical.
We found this circuit in the July 1969 Radio Electronics magazine. The circuit uses a coupler made...
The FET of this circuit of a 1971 publication may be the BF245. The circuit serves as a voltage...
This circuit was obtained from an American documentation from 1969. The operational amplifier and...