I saw a SA-1520 at a garage sale and was wondering if it would sound better (i.e. be considered an upgrade) than my Onkyo TX-4500. It came with a matching tuner and equalizer, which would lead me to believe that it might not be that good...? I can't really find much information online, other than that it was made in the 80s and came with the other matching components (BPC?). Any leads would be appreciated!