Table of Contents
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Chapter 1: Origins and Destination of Hollow-State Audio
- Introduction
- Radio
- Phonographs
- Television
- Other Markets
- The Birth of Hollow-State Electronics
- Early Tubes
- Triodes
- Tetrodes
- Pentodes
- Modern Tube Filaments and Envelopes
- New Life for Vacuum Tube Technology
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Chapter 2: Basics of Hollow-State Electronics
- Hollow-State Amplifiers
- Vacuum Tube Biasing
- Voltage Gain of Amplifier Stages
- The Frequency Response of Hollow-State Amplifiers
- Frequency Response Goals
- Low-Frequency Response
- High-Frequency Response
- Hollow-State Power Amplifiers
- Single-Ended Class-A Amps
- Push-Pull Triode Amplifiers
- Choices: Single-ended or Push-Pull; Triodes or Pentodes?
- Achieving Higher Efficiency with Class AB and B Amplifiers
- Class B Operation
- Transformer-Coupled Push-Pull
- Phase Splitters—Paraphase
- Differential Amplifier (Long-Tailed Pair)
- Single Triode or Split-Load Phase Inverter
- Biasing and the AB Classes
- Feedback
- Complete Push-Pull Power Amplifier
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Chapter 3: Commercial Hollow-State Power Amplifiers
- Classic Tube Power Amplifier Circuits
- Knight 10-W Amplifier
- Heathkit W5M
- Fisher Model 70
- Dynaco Mark II
- McIntosh MC75
- Pro Tube Power Amplifier Circuits
- Western Electric's Early Days
- RCA's Early Days
- Dukane
- Altec Lansing
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Chapter 4: Designing Hollow-State Preamplifiers
- Controlled-Source Theory in Hollow-State Design
- Ideal Current Sources
- Controlled Sources
- Active Loads
- Designing Hollow-State Triode Audio Preamplifiers
- Tube Choices
- Tube Characteristics
- Load Line
- Capacitor Values
- Linearity in Audio Preamplifiers
- Grid-Current Limiting
- Determining Distortion
- Phonograph Preamplifiers
- Dealing with Low Frequencies
- Standardized Equalization
- Phonograph Pickups
- Power Supply Considerations
- Tube-Type Microphone Preamplifiers
- Mixers
- Portable Racks
- Modern Tube Microphone Preamps
- Incorporating Triodes
- Reflected Plate Amplifier
- Starved Amplifier Operation
- Triode Amplifiers
- Low Control-Grid Voltages
- Adding a Dual Op-Amp
- Applying Starved Design to Pentodes
- Space-Charge Tubes and Their Applications
- Types of Space-Charge Tubes
- A Project to Familiarize Ourselves with Design Using Space-Charge Tubes
- The Power Supply
- Control-Grid Bias
- Grid-Leak Biasing
- Changing Triodes
- Input Resistance
- Increasing the Input Resistance by Going Hybrid
- Bias Adjustment
- Modifying the Circuit to Accommodate Parts-Supply Issues
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Chapter 5: Vacuum Tube Characteristics and Load Lines
- Finding Information on Vacuum Tubes
- Data Sheets
- Typical Operation
- Plate and Transfer Characteristic Curves
- Dependence of Parameters on Plate Current
- Selecting the Operating Point for a Hollow-State Amplifier
- First Steps
- Optimizing the Q-Point
- AC Load Lines
- Predicting Performance
- Pentodes and Screen-Grid Voltages
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Chapter 6: The “Tube Sound"
- Understanding Nonlinear Distortion
- Introduction
- Nonlinearity
- Modulation Distortion
- Timbre
- Perception of Distortion
- Frequency Response Graphs
- Solid-State Amplifiers
- The Great Debate
- Overdriving Amplifiers
- How do different Amps distort differently?
- Introduction
- Distortion signatures
- Perceptibility of Distortion
- Other Possible Determinants of “Tube Sound”—Damping Factor
- A Magical "X" Factor”?
- Differences in Amp Sound: how do we find the Truth? (Investigations)
- Accuracy or Pleasantness?
- Subjective Evaluation
- Program Material
- Test Procedures
- Differences in Amp Sound—what is the Truth? (Results)
- The Great Debate: Origin and Analysis
- The Gold Standard of Testing
- Differences in Distortion Spectra
- A/B/X Testing
- Audio Pro's Challenge
- The Search Continues
- Choosing a Side
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Chapter 7: Power Supplies for Hollow-State Audio Equipment
- Overview, Transformers, Rectifiers
- Sections of the Power Supply
- Power Transformers
- Rectifiers
- Voltage Doublers
- Half-Wave Doubler
- Full-Wave Doubler
- Output Waveforms and Voltage Regulation
- Power Supply Design
- Filament Supply
- Sample Power Supply Design
- Setting Specifications
- Rectifier Type and Transformer Voltages and Currents
- Filter Capacitor, Resistor, and Inductor Values
- Bias Supply
- Troubleshooting Power Supplies for Hollow-State Equipment
- Blown Fuses
- Low or Distorted Audio
- Hum
- Complete Failure to Operate
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Chapter 8: Selecting Tube Types
- Which Tube for Which Purpose?
- Pre-WWII
- Miniature Tube Types Introduced
- Octal Triodes that are Still Available
- Pentodes
- Which Power Tube for Which Purpose?
- Triodes, Tetrodes, Pentodes
- Beam Power Tubes
- Power Triodes
- Comparing Hollow-State Rectifiers
- History
- Specifications and Variations
- Swapping Rectifier Tubes
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Chapter 9: Output Transformers
- Introduction
- Why Transformer-Couple the Output?
- Description and Theory of Operation
- Specifying Output Transformers
- Ideal and Real Output Transformers
- Design Parameters: the Physics and Construction of Transformers
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Chapter 10: Tone Controls
- The Introduction and Development of Tone Controls
- Tone Switches
- Electrical Filter Types
- "One-Knob" Continuous Tone Controls
- “Two-Knob" (Bass/Treble) Tone Controls
- Tone Controls: Yes or No?
- Midrange Controls in Instrument Amps, but Not in Home-Stereo Amplifiers
- Guitar-Amp Tone Stacks
- More on Loudness Controls
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Chapter 11: Dynamics Processing with Tubes
- What is "Dynamics Processing?"
- Operating Parameters of Dynamics Processors
- Effects of Dynamics Processing
- Classic Hollow-State Dynamics Processing Approaches
- Voltage-Controlled Attenuators
- Voltage-Controlled Amplifiers
- Compressor Controls
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Chapter 12: Hollow-State Guitar Amplifiers
- The Development of Tube Guitar Amplifiers
- History
- Circuitry
- The Tone Character of Tube Guitar Amplifiers
- Fundamentals and Harmonics
- The Effect of the Speaker
- Tone Controls
- In Which Stage Does Clipping First Occur?
- Distortion in Tube Guitar Amplifiers
- When the Public Developed a Taste for Distortion
- The Basics of Distortion
- Effects of Guitar-Amp Design on Distortion Sound
- Preamp
- Tone Controls
- Driver
- Phase Splitter
- Push-Pull Output Stage
- Output Transformer
- Overdriving the input
- A Solid-State Comparison
- Conclusion
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Chapter 13: Hollow-State Capacitor Microphones
- Design and Development
- Tube Impedance Translators for Capacitor Mics
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Chapter 14: Troubleshooting Hollow-State Equipment
- Elementary: What are the Symptoms?
- Sherlock
- Looking at it
- Deeper and deeper
- Troubleshooting the Tough Ones
- Divide and Conquer
- Testing Tubes
- Continuity Testers
- Emission Testers
- Mutual Conductance Testers
- Dynamic Conductance Tester
- DC and AC Parametric Testers
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Appendix A: Resources (in Order Referenced in Text)
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Appendix B: Tube Data Sheets
