I am trying to design a output filter, a simply one (First order) just to play around with and for some reason when I run the simulation of it its not the correct Cut off frequency which it was designed for.
There's already a High Pass Filter at the input of the Amplifier Fc = 0.320Hz.
This make sense as 560K R and 1uF C has a Fc ~= 0.318Hz
Bode Plot of Node 2:
Whats going on?