Thanks Bobby Jay, just as I suspected the 70mm Baby Boom version was basicaly identical to the 35mm Dolby stereo although vastly superior having the advantage of Discrete audio, and two subwoofers. The way Lucus operates I thouhgt I would never hear this track, and its unlikly it will ever be released. Lucus is partially to blame for this but its also due to the fact that the studios never release these older films with there original 70mm audio. The only film I can think of off the top of my head that did this was a LaserDisc version of Alien which has its 70mm audio and proudly states it on the back cover, this used 5.1 AC3 to play and was also the best sounding version of the film in my opione with the most power behind it, and better then the DVD verions currently available. Although this version of Star Wars was in terms of difference almost identical to the 35mm version I did notice one thing and if in fact this turns out true it would indicate the only unicness between the two tracks. I did not no matter how high I turned up the volume on my receiver hear the echo present in the shaft when Luke and Liea swing across the chasm "I think we took a wrong turn". Naturaly this recordings limited quality might be affecting this, but there should be some indication of the echo being there, should'nt there. Now if only someone out there could find a recording of the 70mm Empire track.