Disc cutting lathe

The cutting stylus engraves a modulated spiral groove corresponding to the audio signal into the lacquer coating of the master disc.

The direct metal mastering (DMM) process uses a copper-coated rather than lacquer-coated disc.

[2] In 1931, German manufacturer Georg Neumann & Co. introduced the AM31 disc-cutting lathe, which employed a direct-drive design.

Two years later, Neumann introduced a portable lathe capable of making recordings on location.

[4] In 1947, the Presto 1D, Fairchild 542, and Cook feedback cutters represented major improvements in disc-cutting technology.