Motion Picture Herald (Mar-Apr 1947)

NEWS AND VIEWS OF TH ARKET AND ITS SOURCES OF SUPPLY New Century Sound Equipment NEWLY DESIGNED sound reproducing equipment emphasizing simplicity in mechanical arrangements with a high degree of selectivity for specific capacity, acoustical and application requirements, has been announced by the Century Projector Corporation, New York. The new equipment, the manufacturer points out, has been based fundamentally on the design of the previous Century systems developed in co-operation with the Western Electric Company. In the announcement the manufacturer states, "Century will welcome requests for assistance in making a proper choice of this equipment to fulfill special requirements. Not only can the initial installation be tailor-made, but should later developments require additional power, reproducer modifications, or other unforeseen specifications, they may be easily added to or subtracted from as changing engineering standards may dictate." THE SOUNDHEADS The "Master" reproducer combines, for filtering, an adaptation of an electromagnetically damped flywheel and an oildamped stabilizer, his dual device is engineered with mechanical simplicity, however, to make it easily serviceable in the theatre. The "Master" has twin exciter lamps, shock-mounted and switch-controlled, providing for quick replacement in case of lamp burnout and an off position for cutting out undesirable portions of leaders, noise, bad splices, etc. Micrometer adjustments are provided for guiding the film, focusing and azimuth control of the optical system. The optical system includes an image-destroying collector lens. This transfers the light, after it passes the film, to the photoelectric cell surface, which varies in intensity over its whole area. This arrangement for freedom from distortion emphasizes variable area sound tracks. Both "Master" and "Standard" reproducers may be equipped with a photoelectric cell panel for use only with those sound systems which require low-capacity cable connections to amplifiers mounted on front walls, or with the Century preamplifiers and volume control for use with the Century amplification systems. They also may be equipped with push-pull optical systems for theatre or studio use. The motor is mounted vertically, and the direct drive arrangement can be adapted to 25-, 50 or 60-cycle induction motor Century "Master" soundhead. "Standard" soundhead, eliminating sound sprocket. operation, or for synchronous mo'.or or interlock motor systems for studios or other high-precision sound reproduction. The "Standard" reproducer, designed especially for small theatres, eliminates the sound sprocket entirely. The film passes from the lower projector sprocket past the scanner drum and rollers to the hold-back sprocket and lower magazine. There is thus only one driven shaft. The new Century amplification system has been especially designed for selection of units to meet either special or conventional requirements. The preamplifier, which fits either the "Master" or the "Standard" reproducer, has one stage of amplification giving, according to the manufacturer, approximately 10 db. gain, and The new Century main amplifier, which uses only two amplifying tubes and is available in ranges of 30-40, 75 and 250 watts. At right it is pictured with door open, showing a. c. exciter lamp power supply arrangement. reduces the output impedance from the reproducer to 600 ohms through a precision variable network. This allows individual volume control from each reproducer and is designed to prevent electrical interference or pick up. MAIN AMPLIFIER Available in ranges of 30-40 watts, 75 watts and 250 watts, the new Century power amplifier is a single, push-pull stage of amplification entirely self-contained and employing only two amplifying tubes, thus departing from design which parallels highgain amplifiers in the power unit. The main amplifier is equipped with a fixed variable attenuator for setting average theatre volume. It may be used as a flat frequency amplifier to within 1 db. from 40 to 20,000 cycles, or may be modified to obtain any frequency characteristic which may be desired. It is factoryadjusted to meet the standard frequency characteristic specified by the Society of Motion Picture Engineers and the Academy of Motion Picture Arts and Sciences. The distortion rating the manufacturer states, is guaranteed to be less than 2% total harmonics, and less than 8% intermodulation from 40 cycles to 10,000 cycles at full 15 watts output. The manufacturer adds that this output can be increased to 30 BETTER THEATRES, APRIL 5, 1947