Tony wrote: > If you do use an output resistor, make it fairly small, like 220 ohms, > that way the attenuation from 100K to 220 makes the normalized input > practically disappear. > IMHO 220r is already a bit high. "most" modules seem to use 100r for the output resistor: 15V @ 100 ohm => 15mA, almost any opamp can handle 15mA Cheers, Theo