Other settings like this can be found on this website. This makes use of old operational amplifiers, as the publication where we obtained, but equivalents can be used.
The configuration shown in the figure is a second order filter (12 dB per octave) with an...
We found this circuit in Radio Electronics magazine from May 1967. The circuit has the tuned...
This circuit is from a 1977 Signetics manual. BC107 transistors can be replaced with BC547 and...