Using two 741 operational amplifiers, this low-pass circuit has a cutoff frequency of 10 kHz. We found it in an article in the magazine Electronics Now from August 1993.
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
This circuit was obtained in an old Elektor. It is a reference, since the integrated products of the...
This circuit was found in a European technical documentation from 1991. It is a circuit that must...