At 02:48 PM 3/22/2011, Olin Lathrop wrote: >Dwayne Reid wrote: > > Shouldn't matter which resistor you change as far as gain is > > concerned. > >As long as the opamp remains stable at the lower gain. Yeah - I specifically asked him what the current gain is and what he=20 want to change it to. I couldn't figure out from his message if he=20 wanted to decrease the gain below unity. You can make most op-amps stable even with gain less than -1 by=20 increasing the noise gain of the op-amp. In other words, you add a=20 gain-set resistor from the (-) input to ground. As long as the noise=20 gain exceeds the minimum gain required for stability, the op-amp=20 remains stable even is the input gain is less than that minimum. dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .