Hi Eric, here is my circuit using the LF411.Since it can go to a max of Vcc-1.5 so i have changed the values.Didnt use the KA358 since it is specified in its datasheet that the i/p can to a max of Vcc-1.5.I will operate the LF411 using 5V.I do want to see the circuit that you come up with since you are a pro at this but just wanted to show and ask whether this will do.I think it works atleast it does in simulation.But i do want to see what approach to you make.Thanks.