What is the cut-off frequency for this low pass filter?
Look for Sallen and Key filter.
Fc = 1/(2 * pi * sqrt(R1 * R2 * C1 * C2))
Or use a calculator, found one here: Sallen-Key Low-pass Filter Design Tool
(It appears to handle &quot;k&quot; and &quot;n&quot;, as a bonus)
Fc = 232 Hz, if you want to check your math.