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. Read more