You changed your original post. I was going to suggest AudioMaster too, but I don't think it can import 16-bit/AD516 samples (like you were asking about at first?). Barring that, I have some vague recollections of programs called something like AIFF and SOX, if those ring any bells? Pretty bare command-line conversion utilities was mostly what I used back in the day, but it's been 20 years...
Edit: Try these:
http://aminet.net/search?query=sox
