Contents:
3--STEREO MULTIPLEX TROUBLESHOOTING
4--INTRODUCTION TO AUDIO AMPLIFICATION
7--SYSTEM EVALUATION AND TROUBLE LOCALIZATION
8--TEST-EQUIPMENT PERFORMANCE VERIFICATION
Hi-fi stereo servicing is a major source of income for shops that are properly equipped and staffed. A reputation for reliability and competence in this field places the technician in a privileged position. Audio enthusiasts are well aware of the fact that true tonality is the chief vehicle of musical meaning; this segment of the home-entertainment market is much more demanding than the TV viewer or the casual radio listener. The dominant characteristics of a hi-fi stereo system are uniform frequency response over the entire audio frequency range, a low percentage of harmonic and intermodulation distortion, and ample stereo separation. The acoustic properties of a hi-fi installation are also of basic concern. In turn, a working knowledge of hi-fi circuitry and troubleshooting procedures must be augmented by full understanding of audio test and measurement procedures, and a practical grounding in the principles of acoustics.
Hi-fi technicians often tend to specialize, because the field is so extensive.
One who aspires to general practice in the hi-fi stereo field must acquire competence in troubleshooting of fm and AM tuners, multiplex adapters, amplifiers, tape recorders, and record players, and must know the fundamentals of speaker repair. He must be fully familiar with the operation of audio oscillators, signal generators, sweep generators, stereo-multiplex generators, oscilloscopes, harmonic-distortion meters, and intermodulation analyzers. It is also very helpful to understand the fundamentals of square-wave generator application.
The keystone of a professional reputation is the ability to provide critical customers with quantitative evaluation of frequency response, percentage of distortion, and dB separation.
This guide covers all components of the hi-fi stereo system except record players and tape recorders, which are the subject of companion volumes in this series. The topics treated in this text include the troubleshooting of equipment (AM tuners, fm tuners, stereo multiplex units, and audio amplifiers), installation of hi-fi speakers, system evaluation, and test-equipment performance verification. It is assumed that the reader is familiar with the basics of AM and fm radios, and with the operation of basic electronic test equipment such as the VOM, the VTVM, and the oscilloscope. The guide is functionally divided according to sections in the hi-fi system, and is further divided according to symptoms. It has been organized to serve as a ready reference to a particular part of the system when a given trouble symptom occurs.
It is my firm belief that this hi-fi stereo servicing guide will be a valuable addition to the libraries of all audio technicians.
Also see: