A couple weeks ago, I wrote about some of the earliest efforts at digital audio recording. I concentrated mostly on systems developed by Denon and Sony which became widely adopted (but also introduced some drawbacks which have made the lives of everyone in the industry more difficult to this day.) What I didn’t mention at all was a system developed independently at 3M, which gets discussed on Wikipedia:

Early June 1978: Sound 80 records Flim and the BB’s debut self-titled album as another direct to disc recording again with the experimental 3M recorder in the background. Again, the acetate is deemed not as good as the digital backup, so the digital master is used for the LP record (Sound80 Records S80-DLR-102). This makes it the first U.S. non-classical digital release. Within 6 months, the hand-built (“very bulky and finicky”) 3M digital recorder is disassembled, rendering the non-standard master tape unplayable. Therefore, no Compact Disc release is possible. The compact disc release of the Saint Paul Chamber Orchestra, which used the same machine, is unexplained.

But it turns out that there is an explanation after all. While the prototype machine sent by 3M to the Sound 80 studios* in Minneapolis was dismantled, a handful of production models were built and marketed, and two of them survive today in working condition. One can be seen here with its proud new owner:

These machines recorded a 16 bit, 50.4kHz signal onto 1-inch magnetic tape traveling at a ridiculous 45 inches per second. A 12.5-inch reel offered 7200 feet of tape for up to 30 minutes of recording time. So some of the earliest milestones in the history of digital recording aren’t completely lost – yet.

*Sound 80 is listed on the National Register of Historic Places. While the groundbreaking work done there with recording audio digitally gets and honorable mention, it’s mostly because it’s where Prince recorded the demos which helped him win his first record contract.