I've noticed the same thing. That seems to be a much more rare ocurrance on the old Quad mixes. Quite often, when the Quads had things you didn't hear in 2ch, it was due to them using an altogether different take. I've scratched my head as to why these missing things crop up. It's either those sounds were so low in the 2ch, or they just weren't there to begin with.
30+ years after the fact, the remix engineer finds the multitrack master. He doesn't have complete notes on the 2ch mix, and puts as much there as he thinks would/should be in 2ch. I'd hope any remix engineer listens to the original, so as not to tinker too much. Still, I can see that it's bound to sound different, no matter how much care is taken. Please don't say that it's easier to pinpoint things in MC. We all know that, or we wouldn't be here. As curious a this phenomenon is, I actually prefer hearing all that extra stuff. You can say I'm not a purist. Yet, if you want to be entirely faithful to the original, go listen to the 2ch version.
30+ years after the fact, the remix engineer finds the multitrack master. He doesn't have complete notes on the 2ch mix, and puts as much there as he thinks would/should be in 2ch. I'd hope any remix engineer listens to the original, so as not to tinker too much. Still, I can see that it's bound to sound different, no matter how much care is taken. Please don't say that it's easier to pinpoint things in MC. We all know that, or we wouldn't be here. As curious a this phenomenon is, I actually prefer hearing all that extra stuff. You can say I'm not a purist. Yet, if you want to be entirely faithful to the original, go listen to the 2ch version.
The 5.1 version is day and nite re: the stereo sacd. I just can't get over the "missing" instruments in the 5.1 that are not present in the 2 channel