hairy_hen is right, the 70mm mix is only very slightly different from the 35mm. The mix on this print is an entirely different beast, made *after* the 70mm 6-track and 35mm stereo mixes (just like the "Story of" LP and the Super 8 digest version). It's obvious that Lucas and Ben Burtt kept tinkering with the mixing throughout 1980, even after the 35mm version was out, and that they carried over some of their changes into the SE in '97.

As I've said before, some of the confusion about the content of the 70mm may stem from the fact that the 8mm, which shares some sound variations with the SE, used the 70mm cut as its picture element. However, the soundtrack was put together *after* the 35mm mix; for example, even though it has the 70mm edit of the Rebel fleet establishing shot, you can still hear some of the tracked "Yoda and the Force" music that was added when the scene was extended.

Anyway, back to the topic at hand: I've started watching PSB, and I haven't gotten as far as any of you, but I noticed another difference. When we see the snowspeeders taking off (after the scene of R2, "Imperial walkers on the north ridge", etc.), there is no music.

In all other mixes previously accounted for, the music starts during that scene of the speeders taking off. In this mix, the music doesn't cut in until the next shot of the walkers.

I had no idea that this was anything more than a mono fold-down of the standard 35mm stereo mix, until I got to that scene and thought "hey, isn't there supposed to be music here?" Then I switched to the stereo track and, sure enough, there was music there that's missing from the 16mm. I immediately pulled up this thread and saw that you all had already found other differences. Good work, everybody!