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Summary
Description45-knock-out.png
English: In some regions, 7-inch 45rpm records were sold for a 1/4 inch spindle with a knock out for playing on a 1 1/2 inch hub. In contrast, in the US for example, the default hole was for a 1 1/2 hub. To play the latter on a 1/4 inch spindle required the insertion of a device called a "single puck."
Date
Source
Own work
Author
SageGreenRider
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