Close the SPST switch.
It looks like capacitors can be used for feedback in op amp circuits. With a capacitor feedback network, the formula for gain for the non-inverting configuration seems to be
Vo = Vi(1+C1/C2).
With a resistor feedback network, the formula is
Vo = Vi(1+R2/R1).
I don't know if this is used anywhere or if it works IRL (I haven't tried it on the breadboard yet, but why shouldn't it work?), but I thought I should share it since I've never seen anything like this before.
