I'm using two potentiometer in amplifier design for controlling gain and offset. the potentiometer that used in offset control works perfect. but that one used in amplifier resistor have a big problem. When it joined to circuit, output signal become too noisy.
My circuit design in this section as follows:
I changed the potentiometer in feedback path, but result is same. Also I cut the offset path and test gain section separate, but output don't changed.
can I help me or explain this problem?
thank you,