Thanks for the calcs Spehro. That's helpful to know. For example I have a circuit that uses 1k pots on 452 ADC channels. Now I know that I could actually use anything up to 10k, and can calculate the impedance if they were powered via a divider (from before the regulator for instance) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics