cosmogrill

Hey, Im looking for a used minidisc for field recordings, with ability to control the level of the Mic input. Now I`m using the MZ-n707, and it doesnt has this feature- there is just one level of mic input sensitivity. Can you inform me about this models? MZ-R91, MZR-900, MZ-R3 , mz-s1, MZR90 , MZR900. I just tell the the models which sales on my area, cause I prefer to check it before I buy. thanks!!!