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Show Thursday, February 8, 1979 Page 3 N US1C You Can Enjoy The Numbers f Ever since the first quarter-notes quarter-notes were set on paper man has been recording music either in graphic terms or by mechanical means from the tin foil clinder of the 1870s to the modern LP. Now a method called digital recording is, in both senses of the word, rewriting the art of musical recording. Digital recording transcribes live music into the binary language lan-guage of computers with virtually none of the distortions distor-tions associated with ordinary ordin-ary analog tape recording. The technique is being hailed as the greatest advance in the recording industry since LPs hit the consumer market mar-ket in the 1950s. To learn more about digital recording The Newspaper interviewed Robert Inge-bretsen, Inge-bretsen, vice president for recording services for Soundstream, Inc. of Salt Lake City. Soundstream was the first company in the United States to offer digital recording services to the record industry. Its first digital tape was made in May of 1975. Soundstream, Inc. offices and production facilities are compacted into the lower floor and basement of a red brick house-size building just off South Temple at 6th East. The setting seems rather subdued for the nation's leading producer of digital records but the company does not actually stamp records. It is contracted by record companies to make digital tapes of recording sessions. The digital recording equipment equip-ment (about 500 lbs. worth) is transported in four steamer steam-er size trunks to wherever the musicians are performing. perform-ing. After the recording session, the tapes are taken back to Salt Lake City where Soundstream can edit, mix and copy them. Finished tapes and digital equipment are then taken tea cutting facility where the disc mast- ers are cut to make LPs. The president of Sound-stream Sound-stream and inventor of the company's digital recorder is Dr. Thomas Stockham. Stockham, a former professor profes-sor at the Massachusetts Institute of Technology and the University of Utah, is one of the nation's leading experts ex-perts in digital signal processing proces-sing and was among the panel of experts that examined ex-amined the infamous 18-and-a-half minute gap in the Nixon tapes. Robert Ingebretsen explains ex-plains the digital recorder invented by Stockham, who had been Ingebretsen's advisor at the U. of U., as "the recording of audio signals in digital form." Before he goes into depth on his definition of digital recording, Ingebretsen first describes how conventional LPs are manufactured. Magnetic master analog tapes are made of a recording record-ing session. The tapes are then edited, mixed and spliced to produce the best sound possible. After a master tape has been completed com-pleted it is transcribed onto master lacquers, shellac surfaced aluminum discs into which record grooves are lathed. A nickel compound com-pound then is electroplated to the lacquers, creating a disc matrix with ridges instead of grooves. The matrix is peeled off the lacquer and electroplated to produce grooved mothers which are in turn electroplated electro-plated to produce ridged stampers. The stampers are the actual form to which the polyvinyl is formed to produce pro-duce LPS. In each step of the process a number of casts are made from each previous form (10 stampers can be made from one mother, for example) so that up to 50,000 LPs can be produced from one lacquer. "If you get one of the last records made from a stamper stamp-er you're likely to get a pretty lousy record," says Ingebretsen. Since each transcription from tape to lacquer may deteriorate tape quality, making numerous numer-ous lacquers to limit the number of LPs per lacquer won t necessarily guarantee uniform high quality; records. By I' V " T'"r" . , Htm ssJ-"' I r VVo h . 4 -miPrr:" " f '; i - t f - t 111 f i f .. . . ' if It fsf i ?L " "r'f It II fo 1 ir&y-'. J. ill Bob Ingebretsen and the digital editing machine. But the major problem with making records from master tapes, according to Ingebretsen, Ingebret-sen, is trying to get a faithful tape recording of a musical performance. Tapes are subject sub-ject to a number of weaknesses weaknes-ses (tape speed variations, tape noise, limited frequency response and dynamic range, print-through, etc.) that can distort the sound. To circumvent such problems prob-lems some record companies a few years ago began producing direct-to-disc LPs for performance fussy audio-philes. audio-philes. In direct-to-disc recording the intermediate magnetic analog taping step is bypassed bypas-sed and the music is lathed onto a lacquer as it is performed. While this method meth-od produces records of higher fidelity it too has j problems. There can be no editing of direct disc performances perfor-mances so the recording artists are under intense pressure to complete a perfect performance for one record side length of time. Also, since there is no master tape from which to make numerous lacquers the number of records that can be produced is quite limited. Digital recording, says Ingebretsen, is the answer to the problems of both analog taping and direct-to-disc recording. re-cording. The digital recorder assigns a numerical value to the amplitude waveforms of live music samples. In order to reconstruct a high fidelity representation of the music being recorded, the digital recorder takes some 64,000 samples a second. Each sample is assigned a 16-digit (the more digits the more precise is the recording of the amplitude) binary number num-ber numbers expressed in base two such as 0 and 1 in numerical or graphic terms and on and off in electrical terms (thus one sample, for example, could read as eight zeros and eight ones). This means that each second sec-ond of music performed is recorded as one million bits of information on the digital recorder's computer tape. An electric quartz clock controls the rate of signal sampling and playback. The process is, quite literally, writing music in computer language. "It's like using words to write a book," says Ingebretsen. Inge-bretsen. "To get a copy of the recording one just has a computer duplicate the numbers num-bers onto another tape." An infinite number of exact duplicates, free from the distortions of analog tape copying, can be made from the original number list since numbers, not sound, are being transcribed. Editing is accomplished be rearranging rearran-ging the numbers to get the best sound. Splicing and mixing does not need to involve the alteration of the master computer tapes since transference trans-ference of the binary code from two or more masters onto a blank tape can be done by computer. Repeated playing play-ing of the tapes will not alter the coded material so unlimited unlim-ited lacquers can be made, Continued On Page 10 R E S T A U R A N T Serving Breakfast Daily! Serving Prime Rib Nightly Finest Steak House Cuisine Open 7 days a week for dinner Located in Prospector Square Staying in Shape Could Be the Most Fun You ave All Day. '1 lJ Racquetball, Weight Room, and Whirlpool What used to be the "best kept" secret is now the fastest growing sport in America-racquetball! Racquetball Rac-quetball is a great way to physical fitness for all ages... 7 to 70. Racquet-ball Racquet-ball has caught on in Park City and we're prepared. 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