Re: Take-up Spool Tempo Compensation
By Robbie Rhodes
David Wasson asked, "Why didn't Ampico, with precision automatic perforators, compensate the tempo?"
Well, they did and they didn't! All rolls recorded before 1926 (when Dr. Hickman modified the process) were not compensated; after that date all classical music rolls and some of pop rolls _were_ compensated, such as the Dinner Music series.
The hand-played recordings of Ampico's Classical Music Department were registered with a recording piano which marked the key events on blank paper. After 1926 the paper was pulled by a take-up spool, but earlier classic rolls and all pop rolls were produced with constant paper speed, and so would play correctly only if pulled with a capstan-drive spoolbox or equivalent. It's true that the speed/tempo increases slowly as the song is played, but Ampico seemingly ignored the matter! (The Ampico B has a take-up spool of much larger diameter, and so the acceleration is less noticeable.)
Wurlitzer, however, was perforating long-playing music rolls for their big orchestrions and organs, and so they had to provide the compensation for the increasing paper speed.
Even though the tempo increase of a 3-minute pop music roll is only about 5%, it nonetheless annoys me! I have an urge to add a compensator to the motor in my Ampico B, which would keep the paper speed constant by reducing the motor speed as the diameter increases. I just need a little time, though ...!
Robbie Rhodes
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(Message sent Sat 7 Dec 1996, 04:37:50 GMT, from time zone GMT-0800.) |
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