Once encoded, the mp3 should be playable on any mp3 decoder, like
iTunes, Tsunami Pro, Cool Edit Pro, etc. (try http://www.mp3-converter.com/decoders/index.htm for a list of other decoders).
However, not all mp3 are created equal. With the same settings there
can be differences in quality and size amongst the various mp3 encoders.
advanced topic on mp3 header