@Grumpy-MikeI know about the gain is 1. you simply change Ri and Rf Gain = - ( Ri / Rf ) My drawing is an example.QuoteAlso you need a capacitor across the two 1K resistors forming the virtual ground at the +ve input to the amplifier.In my napkin, all resistors are 10 K. You mean a cap // with R1 and a cap // with R2 ?