This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
This common configuration is one of many that can be found in this section using the 555. The...
The load on this amplifier is 8-ohm. We found the circuit in a 1972 Motorola amplifier manual. The...
This circuit is from an old Motorola manual (1999) using an integrated circuit that is not very...