I have been asked more than once Hey Greg, what's with the third tonearm? Why did they do that? It was built when? I was recently contacted by the son of George K. Culbertson, the man who made the Ancient Mix-Master. He is alive, 95 years old, and seemed to be as excited as I was to know that one of his machines is used and cherished, and draws a crowd. Thanks to the generous nature of George's family I can present to you a PDF document of 25 images, including an article with George himself from 1939!
The Ancient Mix Master has 2 turntables and 3 tone arms. The center tone arm can play on either turntable, while each turntable's tone arm can be dropped as well. The resulting sound(s) from the Ancient Mix Master are multiple samples - 2 - from one record and one from the other. I will sometimes use either or both an ECHO PLEX and a ROLAND SPACE ECHO; both analog tape loop machines.
This a pamphlet from 1942 which will take you through the basic steps of making one, and what kind of music to play for a particular scene.
One of my favorite descriptions of a performance was:
"This sounds like the cartoon music in my dreams."
Below are pictures and descriptions of the Ancient Mix Master.
Thanks to Jon Nelson of Some Assembly Required for the idea of this helpful chart.