Stereo-Pak

Stereo-Pak
Stereo-Pak logo
Media typeMagnetic tape
EncodingAnalog signal
Read mechanismTape head
Write mechanismMagnetic recording head
Developed byEarl Muntz
UsageCar audio playback
Stereo-Pak player close up
Stereo-Pak player with cartridge

The Muntz Stereo-Pak, commonly known as the 4-track cartridge,[1] is a magnetic tape sound recording cartridge technology.

The Stereo-Pak cartridge was inspired by the Fidelipac 2-track monaural (audio & cue tracks, later 3-track for stereo) tape cartridge system invented by George Eash in 1954 and used by radio broadcasters for commercials and jingles in 1959. The Stereo-Pak was adapted from the Fidelipac cartridge design by Earl "Madman" Muntz in 1962, in partnership with Eash, as a way to play pre-recorded tapes in cars.[2][3][4]

The tape is arranged in an infinite loop that traverses a central hub and crosses a tape head, usually under a pressure pad to assure proper tape contact. The tape is pulled by tension, and spooling is aided by a lubricant, usually graphite.[5]

  1. ^ "The 4-Track Madman". Archived from the original on July 16, 2004. Retrieved July 7, 2004.
  2. ^ "Analog Stereo Formats". vinylfanatics.com. Archived from the original on November 2, 2011.
  3. ^ Jay Ehler: Earl Muntz Meets George Eash Billboard vol. 84, No. 47, 18 November 1972, p. 62, 76, 78
  4. ^ Barry Kernfeld: Pop Song Piracy: Disobedient Music Distribution since 1929, The University of Chicago Press 2011 ISBN 978-0-226-43183-3
  5. ^ Magnetic sound recording tapes, 1963-04-02, retrieved 2018-05-02