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Small- Signal Audio Design

Book Description

Small- Signal Audio Design is an essential for audio equipment designers and engineers for one simple reason; it enables you as a professional to develop reliable, high-performance circuits.

Table of Contents

  1. Cover
  2. Title Page
  3. Copyright
  4. Contents
  5. Preface
  6. About the Author
  7. Dedication
  8. Acronyms
  9. Chapter 1. The Basics
    1. Signals
    2. Amplifiers
      1. Voltage Amplifiers
      2. Transconductance Amplifiers
      3. Current Amplifiers
      4. Transimpedance Amplifiers
    3. Negative Feedback
    4. Nominal Signal Levels
    5. Gain Structures
      1. Amplification Then Attenuation
      2. Attenuation Then Amplification
      3. Raising the Input Signal to the Nominal Level
      4. Active Gain Controls
    6. Noise
    7. Johnson Noise
    8. Shot Noise
    9. 1/f Noise (Flicker Noise)
    10. Popcorn Noise
    11. Summing Noise Sources
    12. Noise in Amplifiers
    13. Noise in Bipolar Transistors
      1. Bipolar Transistor Voltage Noise
      2. Bipolar Transistor Current Noise
    14. Noise in JFETs
    15. Noise in Op-Amps
    16. Low-Noise Op-Amp Circuitry
    17. Noise Measurements
    18. How to Attenuate Quietly
    19. How to Amplify Quietly
    20. How to Invert Quietly
    21. How to Balance Quietly
    22. Ultra-Low-Noise Design with Multipath Amplifiers
      1. Ultra-Low-Noise Voltage Buffers
      2. Ultra-Low-Noise Amplifiers
    23. References
  10. Chapter 2. Components
    1. Conductors
      1. Copper and Other Conductive Elements
      2. The Metallurgy of Copper
      3. Gold and Its Uses
      4. Cable and Wiring Resistance
      5. PCB Track Resistance
    2. PCB Track-to-Track Crosstalk
    3. Impedances and Crosstalk: A Case History
    4. Resistors
      1. Through-Hole Resistors
      2. Surface-Mount Resistors
      3. Resistor Imperfections
      4. Resistor Noise
      5. Resistor Non-Linearity
    5. Capacitors
      1. Capacitor Non-Linearity Examined
      2. Non-Electrolytic Capacitor Non-Linearity
      3. Electrolytic Capacitor Non-Linearity
    6. Inductors
    7. References
  11. Chapter 3. Discrete Transistor Circuitry
    1. Why Use Discrete Transistor Circuitry?
    2. Bipolars and FETs
    3. Bipolar Junction Transistors
    4. The Transistor Equation
    5. Beta
    6. Unity-Gain Buffer Stages
      1. The Simple Emitter-Follower
      2. The Constant-Current Emitter-Follower
      3. The Push-Pull Emitter-Follower
      4. Emitter-Follower Stability
      5. CFP Emitter-Followers
      6. Improved Unity-Gain Buffers
    7. Gain Stages
      1. One-Transistor Shunt-Feedback Gain Stages
      2. One-Transistor Series-Feedback Gain Stages
      3. Two-Transistor Shunt-Feedback Gain Stages
      4. Two-Transistor Series-Feedback Gain Stages
    8. Discrete Op-Amp Design
    9. High-Input-Impedance Bipolar Stages
    10. References
  12. Chapter 4. Op-Amps and Their Properties
    1. A Very Brief History of Op-Amps
    2. Op-Amp Properties: Noise
    3. Op-Amp Properties: Slew Rate
    4. Op-Amp Properties: Common-Mode Range
    5. Op-Amp Properties: Input Offset Voltage
    6. Op-Amp Properties: Bias Current
    7. Op-Amp Properties: Cost
    8. Op-Amp Properties: Distortion
      1. Op-Amp Internal Distortion
      2. Slew-Rate-Limiting Distortion
      3. Distortion Due to Loading
      4. Thermal Distortion
      5. Common-Mode Distortion
      6. Bipolar input op-amps
      7. FET op-amps
      8. Rail bootstrapping to reduce CM distortion
      9. Simpler rail bootstrapping
      10. Bootstrapping series-feedback JFET op-amp stages
    9. Selecting the Right Op-Amp
    10. Op-Amps Surveyed: BJT Input Types
      1. The LM741 Op-Amp
      2. The NE5532/5534 Op-Amp
      3. Deconstructing the 5532
      4. The LM4562 Op-Amp
      5. The AD797 Op-Amp
      6. The OP27 Op-Amp
      7. The OP270 Op-Amp
      8. The OP275 Op-Amp
    11. Op-Amps Surveyed: JFET Input Types
      1. The TL072 Op-Amp
      2. The TL052 Op-Amp
      3. The OPA2134 Op-Amp
      4. The OPA604 Op-Amp
      5. The OPA627 Op-Amp
    12. References
  13. Chapter 5. Filters
    1. Passive Filters
    2. Active Filters
    3. Low-Pass Filters
    4. High-Pass Filters
    5. Combined Low-Pass and High-Pass Filters
    6. Bandpass Filters
    7. Notch Filters
    8. All-Pass Filters
    9. Filter Characteristics
    10. Sallen-and-Key Filters
    11. Distortion in Sallen-and-Key Filters
    12. Multiple-Feedback Bandpass Filters
    13. Making Notch Filters
    14. Differential Filters
    15. References
  14. Chapter 6. Preamplifier Architectures
    1. Passive Preamplifiers
    2. Active Preamplifiers
    3. Amplification and the gain-distribution problem
    4. Active Gain Controls
    5. Recording Facilities
    6. Tone Controls
    7. References
  15. Chapter 7. Moving-Magnet Disc Inputs
    1. The Vinyl Medium
    2. Spurious Signals
    3. Maximum Signal Levels on Vinyl
    4. Equalization and Its Discontents
    5. The ‘Neumann Pole’
    6. Implementing RIAA Equalization
    7. Passive and Semi-Passive RIAA Equalization
    8. Calculating the RIAA Equalization Components
    9. RIAA Equalization Component Tolerances
    10. Simulating Inverse RIAA Equalization
    11. Physical Inverse RIAA Equalization
    12. Overload Margins
    13. Cartridge Impedances
    14. Cartridge Loading
    15. Cartridge–Preamplifier Interaction
    16. Cartridge DC and AC Coupling
    17. Discrete MM Disc Input Stages
    18. Op-Amp MM Disc Input Stages
    19. Noise in RIAA Preamplifiers
    20. Noise Results with A-Weighting
    21. RIAA Noise Measurements
    22. Electronic Cartridge Loading for Lower Noise
    23. Subsonic Filters
    24. Combining Subsonic and Ultrasonic Filters
    25. References
  16. Chapter 8. Moving-Coil Head Amplifiers
    1. Moving-Coil Cartridge Characteristics
    2. Amplification Strategies
    3. Moving-Coil Transformers
    4. Moving-Coil Input Amplifiers
    5. A New Moving-Coil Amplifier Configuration
    6. The Complete Circuit
    7. Performance
    8. References
  17. Chapter 9. Volume and Balance Controls
    1. Volume Controls
    2. Volume Control Laws
    3. Loaded Linear Pots
    4. Dual-Action Volume Controls
    5. Tapped Volume Controls
    6. Slide Faders
    7. Active Volume Controls
    8. The Baxandall Active Volume Control
    9. A Practical Baxandall Active Gain Stage
    10. Potentiometers and DC
    11. Motorized Potentiometers
    12. Stepped Volume Controls
    13. Switched Attenuator Volume Controls
    14. Relay-Switched Volume Controls
    15. Transformer-Tap Volume Controls
    16. Integrated Circuit Volume Controls
    17. Balance Controls: Passive
    18. Active Balance Controls
    19. Mono/Stereo Switches
    20. Width Controls
    21. References
  18. Chapter 10. Tone Controls and Equalizers
    1. Passive Tone Controls
    2. Baxandall Tone Controls
      1. The Baxandall Two-Capacitor LF Control
      2. The Baxandall Two-Capacitor Tone Control
      3. The Baxandall Two-Capacitor HF Control
      4. Switched-Frequency Baxandall Controls
    3. Variable-Frequency LF and HF EQs
    4. Tone-Balance Controls
    5. Middle Controls
      1. Fixed-Frequency Baxandall Middle Controls
      2. Three-Band Baxandall EQ in One Stage
      3. Wien Fixed Middle EQ
      4. Sweep Middles
      5. The Single-Gang Sweep Middle
    6. Switched-Q Variable-Frequency Wien Middle EQs
    7. Switchable Peak/Shelving LF/HF EQs
    8. Parametric Middle EQs
    9. Graphic Equalizers
    10. References
  19. Chapter 11. A Complete Preamplifier
    1. Architecture and Philosophy
    2. The Line Inputs
    3. The High-Impedance Input Buffer
    4. The Tone-Control Stage
    5. The Active Gain Stage
    6. Performance
    7. References
  20. Chapter 12. Mixer Architectures
    1. Performance Factors
    2. Mixer Internal Levels
    3. Mixer Architecture
    4. The Split Mixing Architecture
    5. The In-Line Mixing Architecture
    6. A Closer Look at Split-Format Modules
      1. The Channel Module (Split Format)
      2. Effects Return Modules
      3. The Group Module
      4. The Master Module
      5. Talkback and Oscillator Systems
    7. The In-Line Channel Module
  21. Chapter 13. Microphone Preamplifiers
    1. Microphone Preamplifier Requirements
    2. Transformer Microphone Inputs
    3. The Simple Hybrid Microphone Preampilifier
    4. The Balanced-Feedback Hybrid Microphone Preampilifier
    5. Microphone and Line-Input Pads
    6. The Padless Microphone Preampilifier
    7. Capacitor Microphone Head Amplifiers
  22. Chapter 14. Line Inputs
    1. External Signal Levels
    2. Internal Signal Levels
    3. Input Amplifier Functions
    4. Unbalanced Inputs
    5. Balanced Interconnections
      1. The Advantages of Balanced Interconnections
      2. The Disadvantages of Balanced Interconnections
    6. Balanced Cables and Interference
      1. Electrostatic Coupling
      2. Magnetic Coupling
      3. Ground Voltages
    7. Balanced Connectors
    8. Balanced Signal Levels
    9. Electronic vs. Transformer Balanced Inputs
    10. Common-Mode Rejection
    11. The Basic Electronic Balanced Input
    12. Common-Mode Rejection: The Basic Balanced Input and Op-Amp Effects
    13. Op-Amp Frequency Response Effects
    14. Op-Amp CMRR Effects
    15. Amplifier Component Mismatch Effects
    16. A Practical Balanced Input
    17. Variations on the Balanced Input Stage
      1. Combined Unbalanced and Balanced Inputs
      2. The Superbal Input
      3. Switched-Gain Balanced Inputs
      4. Variable-Gain Balanced Inputs
      5. High-Input-Impedance Balanced Inputs
      6. The Inverting Two-Op-Amp Input
      7. The Instrumentation Amplifier
    18. Transformer Balanced Inputs
    19. Input Overvoltage Protection
    20. Low-Noise Balanced Inputs
    21. Low-Noise Balanced Inputs in Real Life
    22. Ultra-Low-Noise Balanced Inputs
    23. References
  23. Chapter 15. Line Outputs
    1. Unbalanced Outputs
    2. Zero-Impedance Outputs
    3. Ground-Canceling Outputs
    4. Balanced Outputs
    5. Quasi-Floating Outputs
    6. Transformer Balanced Outputs
    7. Driving Heavy Loads
    8. Reference
  24. Chapter 16. Signal Switching
    1. Mechanical Switches
    2. Input-Select Switching
    3. The Virtual Contact
    4. Relay Switching
      1. Electronic Switching
      2. Switching with CMOS Analog Gates
      3. CMOS Gates in Voltage Mode
      4. CMOS Gates in Current Mode
      5. Series-Shunt Current Mode
      6. Control Voltage Feedthrough in CMOS Gates
    5. Discrete JFET Switching
      1. JFETs in Voltage Mode: The Series JFET Switch
      2. The Shunt JFET Switch in Voltage Mode
      3. JFETs in Current Mode
      4. Reducing Distortion by Biasing
      5. JFET Drive Circuitry
      6. Physical Layout and Offness
    6. Dealing with the DC Conditions
      1. A Soft Changeover Circuit
      2. Control-voltage feedthrough in JFETs
    7. Reference
  25. Chapter 17. Mixer Subsystems
    1. Mixer Bus Systems
    2. Input Arrangements
    3. Equalization
    4. Insert Points
    5. How to Move a Circuit Block
    6. Faders
    7. Postfade Amplifiers
    8. Direct Outputs
    9. Panpots
      1. Passive Panpots
      2. The Active Panpot
      3. LCR Panpots
    10. Routing Systems
    11. Auxiliary Sends
    12. Group Module Circuit Blocks
    13. Summing Systems
      1. Voltage Summing
      2. Virtual-Earth Summing
      3. Balanced Summing Systems
      4. Ground-Canceling Summing Systems
      5. Distributed Summing Systems
    14. Summing Amplifiers
      1. Hybrid Summing Amplifiers
      2. Balanced Hybrid Summing Amplifiers
    15. PFL Systems
      1. PFL Summing
      2. PFL Switching
      3. PFL Detection
      4. Virtual-Earth PFL Detection
    16. AFL Systems
    17. Solo-in-Place Systems
    18. Talkback Microphone Amplifiers
    19. Line-Up Oscillators
    20. Console Cooling and Component Lifetimes
  26. Chapter 18. Level Indication and Metering
    1. Signal-Present Indication
    2. Peak Indication
    3. Distributed Peak Detection
    4. Combined LED Indicators
    5. VU Meters
    6. PPM Meters
    7. LED Bar-Graph Metering
    8. A More Efficient LED Bar-Graph Architecture
    9. Vacuum Fluorescent Displays
    10. LCD Meter Displays
  27. Chapter 19. Level Control and Special Circuits
    1. Gain-Control Elements
      1. A Brief History
      2. JFETs
      3. Operational Transconductance Amplifiers
      4. Voltage-Controlled Amplifiers
    2. Compressors and Limiters
      1. Attack Artefacts
      2. Decay Artefacts
      3. Subtractive VCA Control
    3. Noise Gates
    4. Clipping
      1. Diode Clipping
      2. Active Clipping with Transistors
      3. Active Clipping with Op-Amps
    5. Noise Generators
    6. Pinkening Filters
    7. References
  28. Chapter 20. Power Supplies
    1. Op-Amp Supply-Rail Voltages
    2. Designing a ±15 V Supply
    3. Designing a ±17 V Supply
    4. Using Variable-Voltage Regulators
    5. Improving Ripple Performance
    6. Dual Supplies From a Single Winding
    7. Power Supplies for Discrete Circuitry
    8. Larger Power Supplies
    9. Mutual Shutdown Circuitry
    10. Very Large Power Supplies
    11. Microcontroller and Relay Supplies
    12. +48 V Phantom Power Supplies
    13. Reference
  29. Chapter 21. Interfacing with the Digital Domain
    1. PCB Layout Considerations
    2. Nominal Levels and ADCs
    3. Some Typical ADCs
    4. Interfacing with ADC Inputs
    5. Some Typical DACs
    6. Interfacing with DAC Outputs
  30. Index