The Columbia Long-Playing Microgroove Recording System

Abstract

The Columbia LP (long-playing) microgroove recording system was developed to fill the need for music reproduction which would avoid interruptions not intended by the composer, and which would be of excellent quality at a reasonable cost. This allimportant factor of cost and the public's familiarity with the handling of phonograph records made it desirable to solve the task on the basis of records, rather than tape or wire. Standard 78-rpm records were originally designed to generate sound mechanically by direct transfer of energy from the groove of the record to the vibrating diaphragm. Because the entire acoustical energy had to be extracted from the grooves, these had to be quite rugged, and remained so up until now. The new Columbia recording system was an inevitable outcome of the use of electrical amplification between the groove and the loudspeaker. Today, practically no mechanical energy needs to be extracted from the groove, and thus, for the first time, it has been possible to develop much finer grooves, permitting longer playing time and distortion-free reproduction.