by Howard Cummings
[The author is a recording engineer based in Los Angeles who specializes in audio/visual work.]
The pictures on these pages were taken at the Capitol Records cutting studio and pressing plant in Hollywood and Atwater, Ca., respectively. The author's descriptions of the processes involved in cutting a record are based on his observations of these two facilities.
After mixing down from 24 or 16 tracks to 2, adding equalization and echo-reverberation, compressing the dynamic range, placing the instruments in the stereo image. balancing the levels, etc.. the final stereo mix is ready for the disc-cutting studio. This may be associated with a record company, as is the one I recently visited, or it may be one of the many in dependent operations that serve clients from aspiring songwriters to independent record companies. At the cutting studio, the pair of signals from the two-track 1/4-inch master is processed through a tape-to-disc transfer console [1] for final level adjustments. From there it goes to the cutting lathe [2] (which looks some thing like a 2001 turntable) where a high-precision stylus cuts a continuous groove into a lacquer disc.
Lacquer is basically composed of cellulose nitrate, solvents, a castor-oil plasticizer, and dyes, all of which are deposited onto a thin aluminum substrate plate and then carefully dried so that surface irregularities do not develop.
Once a blank has been chosen and carefully inspected for any deformities that might damage his precision cutting stylus, the engineer cuts a reference lacquer for review by the producer. Simple changes, such as overall reverb, eq., or limiting-compression, can be accommodated in-house with the engineer re-cutting to the producer's specifications. Problems beyond these-such as instrument balance or too much reverb-generally result in a step backward to the recording studio mix room.
When the ref is finally approved, "master" lacquer blanks are chosen, this time with ruthless scrutiny since a flaw at this stage will affect all successive stages, right through pressing and packaging. Blanks used for 12-inch LPs are 14 inches in diameter while 45s are cut on 10- to 12-inch discs; the extra size not only provides a banding sample to check signal-to noise and groove geometry, but also facilitates easier handling in plating (the next step).
Due to the wear and tear of the plating process, several masters are usually cut simultaneously. The exact number is finally determined by sales forecasts:
Linda Ronstadt may need a dozen, while a newcomer would need only one or two. Masters are then shipped to one of' the hundreds of pressing plants in this country, where they are coated with a thin layer of metallic silver, making them electrically conductive. Silver has been found to be the best conductor that will adhere to lacquer, accept a nickel coating, and separate easily from nickel.
The silvered lacquer is then electroplated to a carefully measured thickness in a pure nickel solution bath. This forms a negative image "metal master:' which is removed from the solution, separated, and inspected for imperfections. If none are found, it is washed in distilled water and a scrubbing solution, cleaned, and polished [3].
The positive-image "mother" is made from this negative master [4]. again by means of immersion in a nickel solution (above 100 degrees) for about an hour.
After cleaning, it goes to the "mother tester." who plays it through complete [5]. If he finds any defects, a high-powered microscope is called in to determine when the flaw occurred-in plating or in cutting [6]. If in plating, and if it is superficial enough, jeweler-type precision "pricking" tools can be used to remove it. If that doesn't work, it may be necessary to go as far back as the cutting studio.
Once the mother tester has given his okay. the mother goes to production control to be made into a stamper. It is played through completely after every sixth stamper is made (the stamper's life-span is also limited) to make sure that no damage has occurred along the way. The stamper is processed in much the same way as the mother but takes less time in the plating cycle and has a thinner nickel coating. Once stampers have been made for both sides of the record, they are positioned facing each other on the record press to achieve a waffle-iron effect on the "batter," polyvinyl chloride. PVC, which originates in a clear granular or powdered form, is shipped in bulk loads to the plant, where it is pumped through a silo, a blender, and then to a "closed-tube" system to avoid any chance of contamination. It is then combined with other materials, including chemical stabilizers--for stiffening and heat tolerance--and carbon black, which gives records their characteristic appearance. Black is used for a number of reasons: It makes track location easier, covers cosmetic defects, and--significantly--costs about half of what other colors do.
What about adding antistatic agents and extenders? (An extender is a clay-type filler that is compatible with, but less expensive than, vinyl and is often the source of surface noise.) Capitol's response: "Our records are 99 percent pure vinylite [stabilizers making up less than 1 percent of the vinyl]. We don't add extenders because they hurt the quality of the product. As for antistatic agents. some have been tried. but they've never proven 100 per cent effective. We feel the added cost doesn't warrant it." To get back to our "batter." the PVC and any additional ingredients are loaded into an extruder which looks something like a meat grinder-where they are heated for softening and. in a matter of seconds, they leach the press in biscuit form, ready for stamping.
The pressing itself is accomplished by a hydraulic air and water system controlled through air-operated valves and a heating-and-cooling process. The stamper dies are steam-heated to 350 degrees to allow the PVC to flow into every groove. Then the PVC biscuits. approximately 2 by 3 by 1 inches in size, are pre heated to 300 degrees and inserted into the press [7], either manually or automatically. Through compression molding and steam injection, a flat record is formed in approximately 30 seconds under a pressure of 60 tons per square inch Just before the press opens, cold water is pumped in to chill the die to 95-100 degrees, making the finished disc rigid and easier to re move. Labels are applied and the holes punched during pressing. Flash. or excess vinyl, is trimmed off after the record has come off the press and been inspected visually. A seven-inch circular punch trims 45s in one go, while a high-speed edge trimmer eliminates the excess on LPs [8]. The record then drops to a spindle and is transferred to the testing areas. Here it is inspected for bad labels, scratches, pits, dirt, rough edges--anything that might detract from its physical appearance. Next it goes to quality control, where approximately 10% of the day's total production is inspected for master numbers, sequence and number of songs, and again for surface blemishes. One disc per box of twenty-five is then weighed, checked for defects that may have occurred in pressing. and played for surface noise check [9].
If either aural or visual examination reveals a problem, a "stop order" is written and the stampers re placed before any further production takes place. If not, the record is inserted into a white bleached inner sleeve. When I asked about using plastic-lined sleeves as they do in Europe. I was told that the cost of five cents more per sleeve was the reason we don't see them often in this country.
The album cover. inserts (posters. etc.), record, and inner sleeves are collated, and the package proceeds via conveyor belt first to a plastic shrink-wrap area and then to a 300-degree tunnel where the excess wrap (about 1/2-inch all the way around) is shrunk to the final dimensions.
The albums are then packed, twenty-five to a carton, and delivered to the shipping department for their journey to various distribution centers around the country. The total time elapsed in the pressing plant varies greatly: assuming normal scheduling, six to eight weeks for a forecasted million-seller; for a projected 300,000, it is three to four weeks. However. if an album has been held up in the recording stage and is long overdue, as little as twenty-four hours has been known to elapse from lacquer to shipping dock! What with all the product that is released these days and the tight playlists. there are a great many LPs that never get beyond the racks in the record stores. So what about recycling all that unsold vinyl? According to one plant manager at Capitol. "Almost every company uses a certain percentage of remitted materials we use maybe 20 or 30 percent." The process? "The labels are removed with a wetting agent to penetrate the paper so it comes off easier. Afterward, the material is ground up, delivered to the press, and then heated." No one will say how widespread this practice is.
But there are frequent cries that quality is "going down the drain" and that records are "too high-priced for what you get." Nonetheless, sales are healthier than ever and will continue to increase; only the audiences will change. For if you like the artist, it's the only game in town.
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(High Fidelity, Nov. 1977)
Also see:
What's Out In Semipro Consoles