In this article, I’ll describe a few easy steps that will convert any Sallen-Key (SK) or multiple feedback (MFB) active filter from a single-input filter to a summing active filter that gives the same ...

Here is another little analog computer example. Instead of the 100-kΩ resistor going from the summing point of A4 to the output of A3, we could have a 50-kΩ resistor going to the tap of a 50-kΩ pot, ...