Unlike the consumer-marketed
8-track cartridge developed in 1964 by
Bill Lear which had the
pinch roller integrated into the cartridge, the Fidelipac cartridge had a hole in the right-hand bottom front corner of the cartridge, where the pinch roller built into the player would swing up into place to hold the tape against the
drive capstan. While later machines from ATC, ITC, Harris, and others had the pinch roller automatically engage the cartridge when the play button was pressed (the capstan motor was already running when the cart was inserted), early machines such as Sparta, Spot-matic, and others required the operator to also push or pull a separate lever to move the pinch roller into place before playback could begin. The 8-track cartridge tape speed was slower (
ips compared to Fidelipac's ips) and did not have adequate tape support pads, and thus was not "broadcast quality." The lower speed and narrower tracks in 8-track cartridges led to higher noise and reduced frequency response. The 8-track design also lacked a cue track. There were four sizes of Fidelipac carts available — the inch-wide by two-inch long AA (single) size, capable of carrying the same material as a 45 RPM EP (six minutes per track) 4-inch-wide A size (Fidelipac Model 300, 350 and MasterCart), which was a standard 8-track size cart with maximum minute playing time at 7.5 ips (this was the most common and widely used size of Fidelipac cart); the 6-inch-wide B size (Fidelipac Model 600), a larger cartridge designed for holding longer programs; and the even larger 8-inch-wide C size (Fidelipac Model 1200), often used for
background music applications like the
Rowe Customusic. The A size Fidelipac cartridge was later adapted by
Earl "Madman" Muntz in partnership with George Eash in 1963 for his
Stereo-Pak cartridge system (also known as a
4-track cartridge). Several instances of B-size and C-size carts were also produced for a limited time to accommodate 2, 3 or 4-LP sets on tape. These differed in two ways — the number of tracks used (four in this case, with two played back at a time to provide a total of two programs of stereo audio), and the tape speed ( ips—the same speed as 8-track cartridges, as opposed to Fidelipac's standard ips). Unlike the Fidelipac players which used a stationary head, the Stereo-Pak system used a movable head to switch between the two programs (much like the 8-track format, which also used a movable head to select its four stereo programs). ==See also==