Seventy-five years ago today, the August 28, 1950, issue of Life magazine carried this ad from Zenith announcing the “Cobra-Matic” record changer. A couple of the consoles including it are shown below. “Cobra” is the shape of the tone arm, and “Matic” means that it’s fully automatic.

And it was planned for the future. Who knew what other speeds and sizes of records might show up, so this one was continuously variable for 10 to 80 RPM, to be compatible with all known records, and any that might show up. Record size was also adjustable, so this changer was set for anything.