Valve Amplifiers

Valve Amplifiers has been recognized as the most comprehensive guide to valve amplifier design, analysis, modification and maintenance. It provides a detailed presentation of the rudiments of electronics and valve design for engineers and non-experts. The source also covers design principles and construction techniques to help end users build their own tool from scratch designs that work. The author's approach walks the reader through each step of designing and constructing, starting with an overview of the essential working principles of valve amplifiers, the simple and complex stages, the process of linking the stages, and completing the design.

The book is comprised of seven chapters all of which include a DIY guide discussion of practical aspects. The text starts with familiarization of the fundamentals of electronics, which are essential for designing and building valve amplifiers. Particular attention has been paid to providing solutions for questions that are commonly asked and faced by beginners in valve designing and construction.

Valve Amplifiers is a masterful hands-on guide for both experts and novices who work with tube audio equipment, and for electronic hobbyists, audio engineers, and audiophiles.

• The practical guide to analysis, modification, design, construction and maintenance of valve amplifiers
• The fully up-to-date approach to valve electronics
• Essential reading for audio designers and music and electronics enthusiasts alike

Amateur and professional valve audio designers and enthusiasts

Chapter 1. Circuit Analysis

• Publisher Summary
• Mathematical Symbols
• Electrons and Definitions
• Potential Dividers
• Alternating Current (AC)
• Active Devices
• Silicon Diodes
• Bipolar Junction Transistors (BJTs)
• General Observations on BJTs
• Feedback
• The Operational Amplifier
• References
• Recommended Further Reading

Chapter 2. Basic Building Blocks

• Publisher Summary
• The Common Cathode Triode Amplifier
• The Tetrode
• The Beam Tetrode and the Pentode
• The Cascode
• The Charge Amplifier
• The Cathode Follower
• Sources and Sinks: Definitions
• The Common Cathode Amplifier as a Constant Current Sink (CCS)
• The Cathode Follower with Active Load
• The White Cathode Follower
• The μ-Follower
• The Shunt-Regulated Push–Pull Amplifier (SRPP)
• The β-Follower
• The Cathode-Coupled Amplifier
• The Differential Pair
• Semiconductor Constant Current Sinks
• References
• Recommended Further Reading

Chapter 3. Dynamic Range: Distortion and Noise

• Publisher Summary
• Distortion
• Digital Concepts
• The Fast Fourier Transform (FFT)
• Designing for Low Distortion
• Signal Amplitude
• Grid Current
• Distortion Reduction by Parameter Restriction
• Distortion Reduction by Cancellation
• DC Bias Problems
• Individual Valve Choice
• Coupling from One Stage to the Next
• Distortion and Negative Feedback
• Carbon Resistors and Distortion
• Noise
• Noise from Resistances
• Noise from Amplifying Devices
• Noise in DC references
• References
• Recommended Further Reading

Chapter 4. Component Technology

• Publisher Summary
• Resistors
• General Considerations on Choosing Resistors
• Capacitors
• Different Types of Capacitors
• General Considerations in Choosing Capacitors
• Magnetic Components
• Inductors
• Transformers
• Why Should I Use a Transformer?
• General Considerations in Choosing Transformers
• Uses and Abuses of Audio Transformers
• Thermionic Valves
• Individual Elements of the Valve Structure
• Thoriated Tungsten Filament Fragility
• References
• Recommended Further Reading

Chapter 5. Power Supplies

• Publisher Summary
• The Major Blocks
• Rectification and Smoothing
• Regulators
• Common-Mode Interference
• Practical Issues
• A Practical Design
• Adapting the Power Supply to the EC8010 RIAA Stage
• References
• Recommended Further Reading

Chapter 6. The Power Amplifier

• Publisher Summary
• The Output Stage
• Classes of Amplifiers
• The Push–Pull Output Stage and the Output Transformer
• Output Transformer-Less (OTL) Amplifiers
• The Entire Amplifier
• The Driver Stage
• The Phase Splitter
• The Input Stage
• Stability
• Classic Power Amplifiers
• New Designs
• Single-Ended Madness
• The Scrapbox Challenge Single-Ended Amplifier
• Obtaining more than Single Digit Output Power
• Driving Higher Power Output Stages
• The Crystal Palace Amplifier
• The Bulwer-Lytton Scalable Parallel Push–Pull Amplifier
• References
• Further Reading

Chapter 7. The Pre-Amplifier

• Publisher Summary
• Input Selection
• Volume Control
• Balance Control
• Cable Driver
• Tone Control
• Obtaining a Clean Signal from Analogue Disc
• RIAA Stage Design
• A Simplified Example RIAA Stage
• 3180 μs and 318 μs Equalisation
• The EC8010 RIAA Stage
• The Balanced Hybrid RIAA Stage
• References
• Recommended Further Reading

Appendix

• Valve Data
• Standard Component Values
• Resistor Colour Code
• Plastic Capacitor Coding
• Cable
• Square Wave Sag and Low Frequency f−3 dB
• Playing 78s
• Equalisation
• Sourcing Components: Bargains and Dealing Directly
• References