It is possible if you are connecting your MD to your UA5 via analog connections, and on most portable MDs, the only analog out is a headphone jack. That will work, connect the headphone out to the back RCA inputs, find a good clean level, and convert that way. But you cannot go digi out of an MD deck (assuming you have a deck that goes digi out), digi in to the UA5, then USB into a computer. That will not work, because the digi through is disabled by the modification.