Short of having access to a magnetic stereo copy of the 1956, 1963, or 1969 releases, the stereophonic vinyl and reel tape releases are technically the closest you can get to the “original” Fantasound, but not without its own warts. The original stereo tracks had zero reverberations baked into the final mix-- dry as a bone all the way through, and that’s exactly how it sounds on the surviving recordings used in the mag stereo prints. So the reverberations weren’t “removed” in the 1990 reissue-- they were never there in the first place. So, while the dynamic effect of hearing the score play in a concert hall does make the commercial pressings a worthwhile listen (I can’t count how many times I’ve enjoyed them), it’s ultimately an artificial effect, and the release still has the issue of a faint phantom centre channel that needs to be adjusted for proper listening, as well as occasional hard pans that aren’t nearly are strong as they are on the mag tracks.
Wow thanks Tony, never realized the reverbs were artificially added! Honestly that might put an end to my hunt for the older releases as I though all this time the restorations pulled the reverbs as part of a blanket NR to the noisy tracks. Have to change my whole perspective on what I thought was the “real” Fantasia sound haha.
EDIT: After Tony mentioned about the mono being a basis for the 1990 release, I did a playback on my VHS and switched to the mono (non hi-fi stereo) track and listened to Ave Maria, and sure enough it’s the same mix as the mono LP I have, complete with special looped ending not in the the stereo mix (both the LP and VHS track) which extended the fade long enough to match the fade out of the video. Amazing! I really need to give this tape more credit than I do.