I suggested a 2 stage signal conditioner with the attenuation (read voltage divider built into the second stage), The first stage is for isolation and buffering to a lower impedance (More Current) and a negative gain built into the second stage, level shifting to offset the 5V issue mentioned a couple of pages back and the final benefit is a very low impedance output that is relatively noise immune and the second stage can have some negative AC feedback added to eliminate what ever junk that might be along for the ride... or not... Really simple. Bob