This is a relatively well known ABY circuit available on the internet.
I have two questions about this circuit : 1) What does the RC network (in the secondaries) do in the output of the transformer? My guess is that it's some sort of filter. 2) what is the point of the two resistors (on the opamps driving the primaries) on the opamp. They don't seem to be providing any gain?
Below is my attempt at an isolated buffer. The aim is to provide a potentiometer giving attenuation (not to silence, just to allow adjustment based on the output differences of various guitar pickups) in one direction and some gain in the other (about 2x gain).
As you can see I've just added some gain to the opamp, and a pot on the output. LTSpice shows this working perfectly. I've left the original RC network in place. What effect on that will the POT I've added have? Is there a better way to do this?