Open reel tape is a magnetic tape format for audio where the tape is not enclosed in a cartridge or cassette, but held on a reel or spindle and threaded manually through the tape head assembly and attached to a take-up reel.
Magnetic tape was first developed in the 1930s in Germany, and after the war the technology was taken to America by Jack Mullin and developed commercially by Ampex with investment from Bing Crosby. The first commercial tape recorder (the Ampex Model 200) was released in 1948.
Open reel tape recorders for domestic and educational use become available by the late 1940s.
Open reel tape recorders for professional use generally use large metal reels (mostly 10½-inches) with large centre holes, which eventually become standardised and known as NAB (National Association of Broadcasters) reels, as opposed to domestic open reel tape recorders which generally used smaller plastic reels and smaller ‘cine spindle’ hubs. Tape generally runs at 15 or 30-inches per second.
Initially, tape was ¼-inches wide and used a single track. Over the years, multitrack recording become common, and by 1968, up to 24 tracks could be recorded onto 2-inch wide tape. The 2-inch 24-track tape reel became the most common format in professional recording studios throughout most of the 1970s and 1980s, but other widths (¼-inch, ½-inch and 1-inch) were also available.
Open reel tape recording was main recording format used by professional recording studios until the late 1980s when digital audio recording techniques began to allow the use of other types of media (such as Digital Audio Tape (DAT) and hard disks). Tape is still used by some recording studios, often to record digital tracks to, to effect a ‘natural’ and ‘warmer’ sound.