Disk-Cutting & Recording Lathes

Disk-Cutting & Recording Lathes

Georg Neumann & Co. disk-cutting machine model R20 for wax masters ca. 1932 property of Deutsches Rundfunk Museum, shown at the Audio Engineering Society 94th convention in Berlin, March 16-19, 1993, from AES Journal, May 1993

Neumann AM-131 disk recording lathe with Lyrec SM-8/3A synchronous drive. "Together the produce flawless fidelity disks for many discriminating companies coast-to-coast. The motor, constructed of the finest Swedish steel, is actually three separate motors in one, operating without belts, gears or chains, for the greatest possible cynchronous precision. World famous for condenser microphone craftsmanship, Neumann has spared nothing to achieve the ultimate in disk recording. Everything is included: standard U.S. inspection microscope, stylus heating, vacuum chuck turntable, suction fixtures, automatic cutter lift, and much, much more. All lathe models are equipped with the same Lyrec synchronous drive. Prices range from $4950 (pictured above) to $12,000 by purchase or lease. Whether you're planning your first lathe, considering an addition, or converting your present lathe to the Lyrec synchronous drive, write or wire collect for complete information to Dept. L. * Electronic 16-2/3 rpm speed converter available as an acessory." (Gotham Audio Corp. ad from Audio, July 1965, p. 15)

Vitaphone engineer George Groves at a 1925 electrical disc recording machine, photo from AT&T exhibit "The Dawn of Sound"

John Mullin demonstrates a Vitaphone disk lathe ca. 1927, clip from An Afternoon With John T. Mullin videotape produced by the Audio Engineering Society. John Mullin was born in San Francisco in 1913 and spent a lifetime as an engineer, inventor, collector and historian of recording devices.

stereo disc cutter on the cover of a special hifi issue of Electronic World. "Our cover this month shows a lacquer master of a special stereo disc being cut at Olmstead Sound Studios in New York City, as arranged by Audio Fidelity. The cutting head being used is a Westrex 3C that costs over $4000. It is carefully mounted in a counter-balanced and spring-loaded carriage on the cutting lathe. Note the two sets of leads that connect the right- and left-channel audo signals to the cutting head. These leads come from recording amplifiers rated at 150 watts per channel. The rubber suction hose (at the extreme right) draws off the 'chip' formed as the disc is cut. The disc itself is mounted on the heavy, weighted turntable of a Neumann fully automatic cutting lathe. Strobe markings are machined into the table's periphery. The turntable is partly hollow and has a number of small holes drilled into its top face on which the disc rests. The spindle at the center of thetable is also hollow. When a master is being cut, a suction line is slipped over the spindle and the resulting vacuum holds the disc firmly and prevents slipping or warping. The entire cutting lathe costs around $12,000." (from Electronic World, Oct. 1959, p. 55)

Links:

• "Men, Women, and Recording: The History of the Office Dictation Machine" by David Morton at http://www.rci.rutgers.edu/~dmorton/dicta.html