This circuit was found in documentation from the 90s. The operational amplifier admits an equivalent. The circuit has frequency ranges up to 5kHz determined by R1.
The component used, which is not common today, is an electronic attenuator. In this application of the...
Found in Analog Devices documentation, this circuit uses components from the time. Formulas for...
This circuit was found in a Radio Electronics magazine from October 1987. It can be used as a...