Introduced in 1963 by the Revere-Wollensak division of the 3M company, the Revere-Wollensak M–2 tried to do for tape players what record changers did for records: make audio tape easy to use for the average consumer. Users could stack up to 20 of the self-threading cartridges for around 15 hours of stereo music. This is the model M-4, released a year later with a teak and walnut cabinet. Like the M–2, it was a vacuum tube machine. The tape speed was only 1⅞ ips (inches per second), but the coating was a “fine-particle low noise oxide” and the audio quality was “quite respectable.” With the hardwood cabinet it weighed about 40 lbs.

The original version was developed at CBS laboratories by Dr. Peter Goldmark (known for leading the team that developed the LP record). It was demonstrated in 1960, but did not become a product until 1963, when it was marketed by the Revere-Wollensak division of 3M. It was not particularly successful. Cost may have been a factor: the M-4 was expensive, retailing for $459 in 1964 (about $4400 in 2023 dollars). Prerecorded tapes from Columbia were $7.95–8.95 at a time when vinyl albums cost $2–4. The 8-track, introduced in 1965, was a cheaper competitor, as were compact cassettes, introduced in 1963 (though they didn't take off until the mid-1970s).