According to the info at the cartridge database, the loading should be 100 ohms or greater. I suggest trying the settings on the Rhea, I can't remember what the built-in loads are, around this value. Listen for the changes in HF and LF and pick one that sounds best to you. That is the way it is done. IME, the Rhea sounded best with the lowest gain setting you can live with to keep the noise floor down. IMO it is much better to turn the volume up a little more than boost the gain. But you can experiment with that and decide what you like best.
