Ampex used an indirect drive on their first machines- Models 200 and 300. The fine speed adjustment for the capstan drive was accomplished by adding and subtracting the amount of drag applied to the rubber tire coupled through a flywheel to the capstan shaft. A minimum warm up time of 5 minutes was needed before any adjustment to the drive was attempted.
A supplied strobe disc was used to determine the correct amount of drag.
It must have been difficult to maintain speed consistancy between machines , using this method.
No wonder later machines used the vastly superior direct capstan drive motor.
Bob Hodge
Robert Hodge,
Senior Engineer
Belfer Audio Archive
Syracuse University
222 Waverly Ave .
Syracuse N.Y. 13244-2010
315-443- 7971
FAX-315-443-4866