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Razor Tape
Record Player
Reel-to-reel Tape
Reference Level
Roll Off

Razor Tape

From Wikipedia, Chace Audio

Early tape recorders were created by replacing the steel wire of a wire recorder with a thin steel tape. The first of these modified wire recorders was called the Blattnerphone, created in 1929 or 1930. In 1931, Clarence N. Hickman of Bell Labs completed a prototype of a steel tape recorder answering machine. This machine saw little use because AT&T policy forbad the use of answering machines on public telephone lines.

On Christmas day 1932, the BBC first used a tape recorder for its broadcasts. This was a Marconi-Stille recorder – a huge machine using steel razor tape 3mm wide and 0.08mm thick. In order to reproduce high frequency audio, it had to run very fast - 90 meters per minute past the record and playback heads. This required a spool of tape three kilometers long to record a 30-minute program. One reel weighed 25kg - over 50 pounds. If the razor sharp tape broke traveling at 90 meters per minute and weighing over 50 pounds, it could unspool, fly off the machine, and quite easily decapitate anyone in its path. As a result, these machines were always isolated in a separate control room and controlled remotely.

Audio engineers all over the world should thank the Germans for coming up with magnetic tape as we know it today.

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