The beloved 4-track tape cartridge was a rival to 8-track tape cartridges in the late 1960s. Pioneered by Muntz, 4-track tapes are almost exactly the same size, with the same quarter-inch tape and endless loop system, but the space used for each track across the width of the tape is twice as wide. So, to play a whole album, you play through the entire length of tape twice (each time with a left and right channel, making four tracks). In contrast, an 8-track plays through its tape four times.
Because 4-track tapes were only manufactured in the late 1960s, nearly all of them are of albums from that time. Any 4-track cartridge collection will be made largely, or entirely, of albums between about 1966 and 1969. Not every album was released as a 4-track tape, but there are quite a few titles that lucky hunters can find. Often they will say Muntz Stereo-Pak somewhere on the label.
See also: 8-Track Tape Player and Recorder Units
4-track tapes and their pinch wheel
The main difference between 4-track tapes and 8-track tapes is that each 8-track has a pinch roller inside the case, which presses the tape to the player as it passed by. In 4-tracks, there is an empty space there instead. It’s the player that provides the pinch roller. As you insert a 4-track tape in a player, a lever is pushed and the pinch roller swings into place.
A few 4-track tapes were marketed as 4/8-tracks — that is, compatible with both. What that actually meant was that they are standard-issue 4-track tapes, but designed to accommodate a pinch roller adapter that you could buy.
Same album on 4-track and 8-track cartridge. See the hole in the 4-track where the player’s pinch roller will go (red arrow). The 8-track has its own pinch roller in that spot.
See also: 8-track tape cartridge repair tutorial (fully illustrated)
Although short-lived, the 4-track era included some great music, including The Beatles, Frank Zappa, Pink Floyd, all five albums by The Seeds, and many others. 4-track cartridges are much more scarce than 8-tracks, but there are always a few for sale online. To actually play 4-track tapes, you’ll need a 4-track tape player. They were made for the home and car (mostly car), and some units could play both 4-track tapes and 8-track tapes.
BEWARE! Some online sellers confuse 4-track tapes with quadraphonic 8-track tapes. Both may have a large “4” printed on the label. Look carefully when choosing – the album must be from the late 1960s and will quite possibly say Muntz Stereo-Pak on it. Check the images for the absence of a pinch roller to make sure it’s a 4-track tape.
