MP3 is a lossy format compared to native minidisc format or to AIFF. But for moost purposes the lossiness doesn't bother most people. Once you have played the file into your sound recording software you have a file that cam be filtered six ways from sunday depending ont he program you're using to edit it. That means you can even edit the wave form, in some cases select a sample of unwanted noise and remove it throughout the file automatically, add room echo, bass or treble, etc., etc. Depenmds ont he program of choice.

If you're going to burn to a CD and you have enough room use the AIFF or WAV format as source files, not the MP3s you might want to produce for emailing, etc.

A