This variable filter circuit was found in July 1975 Radio Electronics magazine. The circuit uses 3 general purpose op-amps like the 741 and must use a symmetrical source.
This circuit was found in an Electronics World of 1969. The circuit has a drain current of...
This circuit makes use of the Linear Technology LT6100. We find it in a 2005 company manual. The...
I found this circuit in an English publication from 1989. This configuration can be mounted with...