I used a ZYX Airy R-1000 straight into my Concerto preamp. The above stated gain agrees with my figures and the Concerto played my .24 mv cartridge as loud as my other sources. There is a little keypad inside the preamp for each channel. Just move the keys according to the diagram and you'll be able to set it precisely for your cartridge.
If you don't have the diagram for phono settings, contact Rowland and they can mail or fax you one.