>> Op-amps ? > > Care to elaborate? Example circuits? :) Er....um.....I'm exercising my right to remain silent So sorry, was thinking buffers not switches. BTW, presumably these do have to be electronically-controlled selectors ? wbr -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist