Conversation:

the whole idea behind digital recording is that bits never wear out when played back our copied. the medium they're on will slowly degrade in quality, but up to a certain point all the ones will still be ones and all the zeros will still be zeros. if you copy them onto a new medium before that point, all the information is preserved.
so, while some of the information is thrown away when _recording_ sound onto a minidics, there is absolutely no loss when _copying_ it. unless, of course, you copy from your md player to your md revorder through an _analog_ connection, which would be _terrybly stupid_.