There is no 1990 remaster actually (at least not in the US, there may have been one from Japan). Amazon lists 1990 by default for many CDs that have a copyright date of 1989 or earlier. The original mastering for CD was done by Bob Ludwig and the remastered version indicates mastering by the late George Marino. However, it is impossible to distinguish these two versions from one another by just looking at the outer artwork because they both list the same original 1986 copyright year. Looking inside the booklet will tell you which version you have. Hope this answers your question.