X, you've apparently been reading a lot of hogwash about receivers. There's no way that a purely electronic signal going through a receiver and being amplified acquires "soundstaging" characteristics unless special processing to do that(e.g. DPLII)is intentionally applied. Also, Japanese receivers have the same frequency response characteristics as those designed in any other country and therefore sound identical to them.
The features of your present receiver are getting a bit dated and if you want to update for that reason, fine, but don't get taken in by any nonsense about differences in basic sound quality somehow depending on what receiver you use.
