You will need something to power you're mic if it runs off Phantom power. Is you're mini disc HI-MD or one of the old ones. The problem with the mic in on you're MD is that it runs through a shitty built in pre before it writes all those little 1 and 0s. If you go line in it bypasses the built in pre and just writes the music on the disc. The problem w/ line in is that the signal dosn't run as hot a the mic in and usually needs to be boosted.( either by a in line preamp((alot of time pres come with phantom power)) to make the mic more sensitive and thus boost the signal, or by post editing on a computer program such a cool edit or sound forge) What kind of taping will you be doing with you're rig open, or stealth?