Overview of Basic Design Principles 1
1-1 General Considerations, 1
1-2 Tolerance Requirements and Calculations, 5
1-3 Basic Device Tolerances, 14
1-4 Principles of Power Dissipation, 16
1-5 Law of Probability, 23
1-6 Audio Design Pitfalls, 25
1-7 Underwriters Laboratories (UL) Approval, 27
1-8 Black-Box Concept, 29
1-9 .Basic Types of Distortion, 29
1-10 Phon and Mel Units, 34
1-11 Low-Frequency Boost, 35
1-12 Presence Control, 37

Fundamentals of Audio Circuit Design 39
2-1 Basic RC Circuitry, 39
2-2 Input Impedance of an RC Section, 48
2-3 Output Impedance of an RC Section, 49
2-4 Filter Output Voltage, 53
2-5 Frequency Response of Cascaded RC Sections, 55
2-6 RC Bandpass Filter Characteristics. 57
2-7 RC Band-Elimination (Notch) Filter, 59
2-8 Active High/Low-Pass RC Filter Network, 61

Principles of Audio Amplifier Design 65
3-1 General Considerations, 65
3-2 Fundamental Amplifier Design Procedures, 67
3-3 Preamplification versus Power Amplification, 74
3-4 Transistor Load Lines, 78
3-5 Negative-Feedback Principles, 89
3-6 Multistage Negative-Feedback Relations, 104
3-7 Transistor Parameter Variation, 108
3-8 Production Cost Tradeoffs, 109
3-9 Notes on Musical and Speech Wave Forms, 112
3-10 Saturation Currents, 113
3-11 Bootstrapping Method of Feedback, 114
3-12 Frequency Response of Cascaded Stages, 116

Amplifier Bias Stabilization Methods 117
4-1 General Considerations, 117
4-2 Bias Stabilizing Circuits, 123
4-3 Thermistor Stabilization, 131
4-4 Diode Bias Stabilization Circuits, 135
4-5 Transistor Bias Stabilization Circuits, 141
4-6 Temperature Compensation by Breakdown (Zener)
Diodes, 146

Audio Power Amplifiers 151
5-l General Considerations, 151
5-2 Output-Transformers Power Amplifiers, 153
5-3 Transformer Phase Inverters. |53
5-4 Quasi-Complementary Power Amplifiers, 156
5-5 Directly Coupled Loud, 161
5-6 Full Complementary Output Arrangement, 166
5-7 Examples of Innovative Circuit Design, 177

Speaker Circuitry 183
6-1 Speaker Interconnections 183
6-2 Crossover Circuitry, 185
6-3 Speaker Phasing, 190
6-4 Connections for 70.7- and 25-Volt Speaker Sys-
tems, 191

Basic Telephone circuitry
7-1 General Considerations, 195
7-2 Phantom Circuits, 201
7-3 Loading Principles, 202
7-4 Repeaters, 203
7-5 Return Los, 205

Glossary

Appendix 1 Resistor Color Code
Appendix 2 Capacitor Color Code
Appendix 3 Diode Polarity Identification
Appendix 4 Electronic Indistries Associations (EIA) Preferred Values for Resistors
Appendix 5 EIA Preferred Values for Electrolytic Capacitors
Appendix 6 Power Ratios, Voltage Ratios and Decibel Values
Appendix 7 Symbols for Field-Effect Transistors
Appendix 8 Relation of Distortion to Positive Feedback and to Negative Feedback