mypointofview

I like to do audio recordings, so I need a device with Mic-In. I noticed that some MiniDisk recorders offer as an added feature a thing called "Digital Amp" like the RH910 http://www.minidisc.org/part_Sony_MZ-RH910.html. What is Digital Amp, and do I really need this? Since I'm a radio lover too, and the NHF800 http://www.minidisc.org/part_Sony_MZ-NHF800.html has also a Mic-In -- I'm wondering which one to purchase. I want to record ambient sounds for my (semiprofessional) movie clips -- but who knows - maybe I want to record more fancy stuff later too. -- Martin in Los Angeles PS. My only portable audio for the moment is a Sony Clie NZ90 with MemoryStick and CF Card.