How do you make a record?

I don%26#39;t mean "How do you write songs," or "How do you get a record deal," I mean literally, how do you make a 72 RPM record? What%26#39;s the record made of? Are there devices to record to it? Etc.

Answers:

It all starts with the disc recorder or "lathe" as it is often referred to, an amazing piece of equipment designed with a slowly rotating feed screw mechanism and carriage to move a cutting head across the radius of the disc. The accurately shaped cutting stylus, mounted in the head, cuts a precise spiral groove across a flat lacquer coated aluminum disc (acetate) spinning at an exact speed of 33-1/3, 45, or in the old days, 78.26 revolutions per minute, the standard phonograph operating speeds.

Next see%26#39;s the cutting head installed on the lathe, this is simply a phonograph pickup in reverse, that is, feed audio in and get mechanical motion out. Other than its greater size, the specially shaped cutting stylus, and the feed screw mechanism which moves the head across the record to make the spiral groove, the internal workings are very similar. The recording stylus is probably the most important component of the recording process, and was probably first used by Edison in 1877.

Diamond is not a good material for a cutting stylus, but is excellent as a reproducing stylus. Home cutting styli were commonly made of a steel alloy because it was inexpensive to manufacture but most cutting styli for professional use are made of corundum, better known as sapphire which will outlast a diamond and produce superior recordings. Since those early recordings on wax, recording blanks have been called by various names including instantaneous discs, lacquers, acetates, soft-cuts and others. The most accurate is probably "lacquer" because of the fact that they are lacquer coated with a compound of cellulose nitrate, and acetate had little to do with it, although it has become a common name for a lacquer coated disc, and many professionals still use the term "acetate".