DocumentCode :
1049626
Title :
Electrical Reproduction from Phonograph Records
Author :
Kellogg, Edward W.
Author_Institution :
Electrical Engineer, Research Laboratory, General Electric Co., Schenectady, N. Y.
fYear :
1927
Firstpage :
903
Lastpage :
912
Abstract :
A new and improved tool generally means new or improved accomplishments. Great improvements in sound recording and reproduction have been made possible by the thermionic amplifier. Electrical reproduction may be considered in three steps, (1) generation of a voltage by the vibrations of the needle, (2) amplification, (3) conversion of electrical power into sound. The first of these steps involves some interesting mechanical and electrical problems, and it is with these that the paper primarily deals, the problems of amplification and loud speaker design having been discussed in earlier publications to which references are given. Several types of phonograph ``pick up´´ are possible; electrostatic, piezoelectric, electromagnetic, and variable resistance or microphonic. The electromagnetic principle is used in the device now manufactured. Since the moving armature cannot be actually at the needle tip, the little generator must function by transmitting the vibrations from the needle tip through a more or less flexible structure to the armature. Vibrations are inevitably transmitted, but when the requirements of freedom from appreciable distortion and maximum possible output are added, extreme care in design becomes necessary. An analysis is given of the mechanical behavior of the present model of reproducer.
fLanguage :
English
Journal_Title :
American Institute of Electrical Engineers, Transactions of the
Publisher :
ieee
ISSN :
0096-3860
Type :
jour
DOI :
10.1109/T-AIEE.1927.5061431
Filename :
5061431
Link To Document :
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