Audio Electronics

Preface1 Tape Recording The Basic System Magnetic Tape Tape Coatings Tape Backing Materials Tape Thicknesses Tape Widths The Recording Process Causes of Non-Uniform Frequency Response Influence of HF Bias Head Gap Effects Pole-Piece Contour Effects Effect of Tape Speed Record/Replay Equalisation Pre- and De-Emphasis Frequency Correction Standards Head Design Magnetic Materials Tape Erasure Recording Track Dimensions HF Bias Basic Bias Requirements Bias Frequency Bias Waveform Optimum Bias Level Maximum Output Level (MOL) Sensitivity Harmonic Distortion Noise Level Saturation Output Level (SOL) Bias Level Setting The Tape Transport Mechanism Transient Performance Tape Noise Electronic Circuit Design Record/Replay Circuit Design Schematic Layout Sony Pioneer Technics Replay Equalisation Bias Oscillator Circuits The Record Amplifier Input/Output Stage Design Recording Level Indication Tape Drive Motor Speed Control Professional Recording Equipment General Description Mechanical Aspects Electrical Design Multi-Track Machines Digital Recording Systems PCM Encoding Bandwidth Requirements Analogue vs. Digital Performance Editing Domestic Equipment Copy Protection (SCMS) Domestic Systems RDAT, SDAT, CDR, Mini-Disc, DCC2 Tuners and Radio Receivers Background Basic Requirements Transmitter Radiation Pattern The Influence of the Ionosphere Critical Frequency Classification of Radio Spectrum VHF/SHF Effects Why VHF Transmissions? Broadcast Band Allocations Choice of Broadcasting Frequency AM or FM? Modulation Systems Bandwidth Requirements FM Broadcast Standards Stereo Encoding/Decoding GE/Zenith 'Pilot Tone' System Decoder Systems PCM Programme Distribution System HF Pre-Emphasis Supplementary Broadcast Signals Alternative Transmission Methods SSB Broadcasting Radio Receiver Design Tuned Circuit Characteristics SAW Filters Superhet Receiver Sensitivity Stability Crystal Control Barlow-Wadley Loop Frequency Synthesis Phase-Locked Loop Automatic Frequency Control Frequency Meter Display FM Linearity FM Demodulator Types AM Linearity AM Demodulator Systems Circuit Design New Developments Appendices Broadcast Signal Characteristics Radio Data System (RDS)3 Preamplifiers and Input Signals Requirements Signal Voltage and Impedance Levels Gramophone Pick-Up Inputs Ceramic Cartridges DIN Input Connections MM and Variable Reluctance Cartridges RIAA Equalisation MC Cartridges Input Circuitry Moving Coil PU Head Amplifier Design Circuit Arrangements Noise Levels Low Noise IC op. amps Input Connections Input Switching Bipolar Transistor FET Diode4 Voltage Amplifiers and Controls Preamplifier Stages Linearity Bipolar Transistors Field Effect Devices MOSFETs U, V and T Types MOSFET Breakdown Noise Levels Output Voltage Characteristics Voltage Amplifier Design Constant-Current Sources and 'Current Mirrors' Performance Standards Audibility of Distortion Transient Defects TID and Slew-Rate Limiting Spurious Signals and Interference General Design Considerations Controls Gain Controls Tone Controls Baxandall Slope Clapham Junction Parametric Graphic Equaliser Quad Tilt Control Channel Balance and Separation Controls Filter Circuitry5 Power Output Stages Valve Amplifier Designs Early Transistor Circuits Listener Fatigue and Crossover Distortion The LIN Circuit Improved Transistor Amplifier Designs Power MOSFETs Operating Characteristics; V and U Types Output Transistor Protection Safe Operating Area (SOAR) Power Output and Power Dissipation General Design Considerations Bode Plot Slew-Rate Limiting and TID HF Stabilisation Advanced Amplifier Designs Stabilised Power Supplies Output Stage Configurations Alternative Design Approaches The 'Blomley' Circuit The 'Quad' Current Dumping Amplifier Feed-Forward Systems The 'Sandman' Circuit Contemporary Amplifier Design Practice The 'Technics' SE-A100 Circuit Sound Quality and Specifications Design Compromises Measurement Systems Conclusions6 The Compact Disc and Digital Audio Why Use Digital Techniques? Problems with Digital Encoding Signal Degradation During Copying Pulse Code Modulation Quantisation Errors Encoding Resolution Bandwidth and Sampling Frequency Distortion Error Detection and Correction Filtering Aliasing PCM spectrum The Record-Replay System Recording System Layout Analogue to Digital Conversion (ADC) The Replay System Physical Characteristics Optical Readout CD Performance and Disc Statistics Two-Beam vs. Three-Beam Readout Methods 0-1 Digit Generation Replay Electronics Zero-Signal Muting Eight to Fourteen Modulation Digital to Analogue Conversion Precision Required Dynamic Element Matching Digital Filtering and Oversampling Finite Impulse Response Filters Transversal Filters Attenuation Characteristics Interpolation of Sample Values Dither Effect on Resolution The Bitstream Process Low Resolution Decoding Noise Shaping Error Correction Reed-Solomon Code (CIRC) Techniques Error Detection Addition of Parity Bits Interleaving Faulty Bit/Word Replacement CIRC Performance7 Test Instruments and Measurements Instrument Types Distortion Types Measurements vs. Subjective Testing Types of Test Instruments Signal Generators Sine Wave Oscillators Wien Bridge Oscillators Required Frequency Range Waveform Purity Requirements Amplitude Stabilisation Square-Wave Generation Output Settling Time Very Low Distortion Circuitry Parallel-T Oscillator Designs Digital Waveform Synthesis Frequency Stable Systems Phase-Locked Loop Techniques Function Generators Alternative Waveform Types Square-Wave Testing Distortion Measurement THD Meters Intermodulation Distortion Measurement Spectrum Analysis FFT Analysis Oscilloscopes Method of Operation Sensitivity and Scan Speeds Multiple Trace Displays Time-Base Synchronisation External X-Axis Inputs Lissajoux Figures Use with Stereo Signals X-Axis Signal Outputs Digital Storage Types Resolution8 Loudspeaker Crossover Systems Why Necessary? Cone Design Optimum Frequency Span for LS Drivers Effects of LS Diaphragm Flexure Acoustic Mismatch at Diaphragm Surround LS Diaphragm Types Flat Piston vs. Conical Form Rigid Cone Systems Coil Attachment and Magnet Characteristics Soundwave Dispersion Crossover System Design Effects of Output Superposition Crossover Component Types LS Output Equalisation Active Crossover Systems Active Filter Design Bi-Amplification and Tri-Amplification Bi-Wiring and Tri-Wiring Loudspeaker Connecting Cables9 Power Supplies The Importance of the Power Supply Unit Rejection of Hum and Noise Single-Ended and Balanced Systems Circuit Layouts Valve vs. Solid State Rectifiers Effect of Size of Reservoir Capacitor Peak Charging Currents Circuit Problems Full-Wave Rectifier Systems Half-Wave vs. Full-Wave Rectification Rectifier Circuits Reservoir Capacitor Optimum Size Transformer Types and Power Ratings Output DC Voltage Stacked Lamination vs. Toroidal Types Stabilised PSU Circuits Zener Diodes Bandgap Reference Sources Three-Terminal PSU ICs Effect of PSU on Musical Performance 'Music Power' Ratings Output Circuit Protection Higher Power Regulator Layouts Shunt vs. Series Systems PSU Output Impedance Designs in Commercial Equipment Commercial Power amp. PSUs Output Source Impedance and Noise Battery Supplies Transformer Noise and Stray Magnetic FieldsIndex