This has been answered by a number of people, with no concensus on whether it's a split feed or two distinct mike pickups. I've been told that it's both, at different points in time. One thing worth noting is that while they kept the "unused" take as a backup, they also sometimes used it as an export master (Victor and HMV swapped all the time) and I've noticed some instances where the A turntable has a distinct wow and the non-A one doesn't. (Menuhin: Bruch Concerto w. Ronald conducting.)I've recently started to pay closer attention to matrix numbers. The take numbers appended to the end of them are often instructive. Could someone more knowledgeable than I explain to me the difference between a take listed as "1" and one listed as "1A"? Does the latter mean a dubbing, and, if so, what does this imply?
Thanks for your help.
-Larry Friedman