Valve Amplifiers

Morgan Jones' Valve Amplifiers has been widely recognised as the most complete guide to valve amplifier design, modification, analysis, construction and maintenance written for over 30 years. As such it is unique in presenting the essentials of 'hollow-state' electronics and valve amp design for engineers and enthusiasts in the familiar context of current best practice in electronic design, using only currently available components. The author's straightforward approach, using as little maths as possible, and lots of design knowhow, makes this book ideal for those with a limited knowledge of the field as well as being the standard reference text for experts in valve audio and a wider audience of audio engineers facing design challenges involving valves. Design principles and construction techniques are provided so readers can devise and build from scratch designs that actually work. Morgan Jones takes the reader through each step in the process of design, starting with a brief review of electronic fundamentals relevant to valve amplifiers, simple stages, compound stages, linking stages together, and finally, complete designs. Practical aspects, including safety, are addressed throughout. The third edition includes a new chapter on distortion and many further new and expanded sections throughout the book, including: comparison of bias methods, constant current sinks, upper valve choice, buffering and distortion, shunt regulated push-pull (SRPP) amplifier, use of oscilloscopes and spectrum analysers, valve cooling and heatsinks, US envelope nomenclature and suffixes, heater voltage versus applied current, moving coil transformer source and load terminations. * 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 Front Cover......Page 1 Title Page......Page 4 Copyright Page......Page 5 Table of Contents......Page 6 Preface......Page 10 Dedication......Page 12 Acknowledgements......Page 14 Mathematical symbols......Page 16 Electrons and definitions......Page 17 Potential dividers......Page 30 Alternating current......Page 38 Active devices......Page 59 Silicon diodes......Page 60 Bipolar Junction Transistors (BJTs)......Page 63 Feedback......Page 69 The operational amplifier......Page 72 Further Reading......Page 78 The common cathode triode amplifier......Page 79 The tetrode......Page 101 The beam tetrode and the pentode......Page 103 The cascode......Page 109 The cathode follower......Page 115 Sources and sinks: definitions......Page 119 The common cathode amplifier as a constant current sink......Page 120 The cathode follower with active load......Page 124 The White cathode follower......Page 125 The mu-follower......Page 130 The Shunt Regulated Push-Pull (SRPP) amplifier......Page 135 The beta-follower......Page 140 The differential pair......Page 142 Semiconductor constant current sinks......Page 148 References......Page 155 Further Reading......Page 156 Defining distortion......Page 158 Digital concepts......Page 166 The Fast Fourier Transform (FFT)......Page 169 AC operating point......Page 172 DC operating point......Page 176 Distortion reduction by parameter restriction......Page 181 Distortion reduction by cancellation......Page 184 DC bias problems......Page 185 Individual valve choice......Page 193 Coupling from one stage to the next......Page 204 References......Page 215 Further Reading......Page 216 Resistors......Page 217 Capacitors......Page 226 Different types of capacitors......Page 229 General considerations in choosing capacitors......Page 240 Inductors......Page 244 Transformers......Page 250 Why should I use a transformer?......Page 262 General considerations in choosing transformers......Page 263 Uses and abuses of audio transformers......Page 268 Thermionic valves......Page 270 Individual elements of the valve structure......Page 274 References......Page 304 Further Reading......Page 305 The major blocks......Page 307 Rectification and smoothing......Page 308 Regulators......Page 343 Specification of the power supply......Page 366 A better power supply......Page 380 Further Reading......Page 391 The output stage......Page 392 Classes of amplifiers......Page 398 The push-pull output stage and the output transformer......Page 401 Output Transformer-Less (OTL) amplifiers......Page 408 The driver stage......Page 409 The phase splitter......Page 411 The input stage......Page 422 Stability......Page 423 Classic power amplifiers......Page 427 New designs......Page 438 The 'Scrapbox Challenge' single-ended amplifier......Page 439 HT choke suitability......Page 446 Push-pull sanity......Page 459 The 'Bevois Valley' amplifier......Page 460 The author's prototypes......Page 468 The traditional approach to power > 10 W......Page 470 Driving higher power output stages......Page 473 The 'Crystal Palace' amplifier......Page 475 'Daughter of Beast'......Page 498 References......Page 504 Further Reading......Page 505 The line stage......Page 506 The volume control......Page 515 Input selectors......Page 528 The RIAA disc stage......Page 531 Noise and input capacitance of the input stage......Page 543 Strays and implementing RIAA......Page 552 Basic pre-amplifier compromises......Page 562 A balanced pre-amplifier......Page 563 The perfect line stage......Page 570 The EC8010 RIAA stage......Page 572 Achieving the RIAA equalization......Page 578 Practical RIAA considerations......Page 585 A line stage......Page 587 References......Page 592 Further Reading......Page 593 Valve data......Page 594 Square wave sag and low frequency f-3dB......Page 600 Playing 78s......Page 602 Equalization......Page 604 Standard component values......Page 608 Resistor colour code......Page 609 Sallen & Key filters for active crossovers......Page 611 UK sources of components......Page 615 Bargains and dealing directly......Page 616 References......Page 617 Index......Page 618 Front Cover 1 Title Page 4 Copyright Page 5 Table of Contents 6 Preface 10 Dedication 12 Acknowledgements 14 Chapter 1 Circuit analysis 16 Mathematical symbols 16 Electrons and definitions 17 Potential dividers 30 Alternating current 38 Active devices 59 Silicon diodes 60 Bipolar Junction Transistors (BJTs) 63 General observations on BJTs 69 Feedback 69 The operational amplifier 72 References 78 Further Reading 78 Chapter 2 Basic building blocks 79 The common cathode triode amplifier 79 The tetrode 101 The beam tetrode and the pentode 103 The cascode 109 The cathode follower 115 Sources and sinks: definitions 119 The common cathode amplifier as a constant current sink 120 The cathode follower with active load 124 The White cathode follower 125 The mu-follower 130 The Shunt Regulated Push-Pull (SRPP) amplifier 135 The beta-follower 140 The differential pair 142 Semiconductor constant current sinks 148 References 155 Further Reading 156 Chapter 3 Distortion 158 Defining distortion 158 Digital concepts 166 The Fast Fourier Transform (FFT) 169 Designing for low distortion 172 AC operating point 172 DC operating point 176 Distortion reduction by parameter restriction 181 Distortion reduction by cancellation 184 DC bias problems 185 Individual valve choice 193 Coupling from one stage to the next 204 References 215 Further Reading 216 Chapter 4 Component technology 217 Resistors 217 General considerations on choosing resistors 226 Capacitors 226 Different types of capacitors 229 General considerations in choosing capacitors 240 Magnetic components 244 Inductors 244 Transformers 250 Why should I use a transformer? 262 General considerations in choosing transformers 263 Uses and abuses of audio transformers 268 Thermionic valves 270 Individual elements of the valve structure 274 References 304 Further Reading 305 Chapter 5 Power supplies 307 The major blocks 307 Rectification and smoothing 308 Regulators 343 A practical design 366 Specification of the power supply 366 A better power supply 380 References 391 Further Reading 391 Chapter 6 The power amplifier 392 The output stage 392 Classes of amplifiers 398 The push-pull output stage and the output transformer 401 Output Transformer-Less (OTL) amplifiers 408 The entire amplifier 409 The driver stage 409 The phase splitter 411 The input stage 422 Stability 423 Classic power amplifiers 427 New designs 438 Single-ended madness 439 The 'Scrapbox Challenge' single-ended amplifier 439 HT choke suitability 446 Push-pull sanity 459 The 'Bevois Valley' amplifier 460 The author's prototypes 468 The traditional approach to power > 10 W 470 Driving higher power output stages 473 The 'Crystal Palace' amplifier 475 'Daughter of Beast' 498 References 504 Further Reading 505 Chapter 7 The pre-amplifier 506 The line stage 506 The volume control 515 Input selectors 528 The RIAA disc stage 531 Noise and input capacitance of the input stage 543 Strays and implementing RIAA 552 Basic pre-amplifier compromises 562 A balanced pre-amplifier 563 The perfect line stage 570 The EC8010 RIAA stage 572 Achieving the RIAA equalization 578 Practical RIAA considerations 585 A line stage 587 References 592 Further Reading 593 Appendix 594 Valve data 594 Square wave sag and low frequency f-3dB 600 Playing 78s 602 Equalization 604 Standard component values 608 Resistor colour code 609 Sallen & Key filters for active crossovers 611 UK sources of components 615 Bargains and dealing directly 616 References 617 Index 618

Morgan Jones' Valve Amplifiers has been widely recognised as the most complete guide to valve amplifier design, modification, analysis, construction and maintenance written for over 30 years. As such it is unique in presenting the essentials of 'hollow-state' electronics and valve amp design for engineers and enthusiasts in the familiar context of current best practice in electronic design, using only currently available components. The author's straightforward approach, using as little maths as possible, and lots of design knowhow, makes this book ideal for those with a limited knowledge of the field as well as being the standard reference text for experts in valve audio and a wider audience of audio engineers facing design challenges involving valves.

Design principles and construction techniques are provided so readers can devise and build from scratch designs that actually work. Morgan Jones takes the reader through each step in the process of design, starting with a brief review of electronic fundamentals relevant to valve amplifiers, simple stages, compound stages, linking stages together, and finally, complete designs. Practical aspects, including safety, are addressed throughout.

The third edition includes a new chapter on distortion and many further new and expanded sections throughout the book, including: comparison of bias methods, constant current sinks, upper valve choice, buffering and distortion, shunt regulated push-pull (SRPP) amplifier, use of oscilloscopes and spectrum analysers, valve cooling and heatsinks, US envelope nomenclature and suffixes, heater voltage versus applied current, moving coil transformer source and load terminations.

* 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

Booknews

For readers with a limited knowledge of the field, Jones, an ex-BBC engineer, examines the theory and practice of designing valve audio amplifiers to the level that they can analyze and modify circuits and build or restore an amplifier. He walks through each step in the process of design, beginning with a brief review of electronic fundamentals. The first edition was published in 1995, and the second includes several new topical sections and example applications. Annotation c. Book News, Inc., Portland, OR (booknews.com)

Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment - as an electronics experimenter, audiophile or audio engineer. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the vacuum tube, whether audio enthusiasts tackling their first build, or more experienced amplifier designers seeking to learn the ropes of working with valves. The practical side of this book is reinforced by numerous clear illustrations throughout. As well as the design and build of new valve amplifiers, complete with constructional projects, Morgan Jones introduces the modification, fault-finding and repair of new and classic equipment. The companion volume to Building Valve Amplifiers, Morgan Jones's Valve Amplifiers, has been widely recognised as the most complete guide to valve amplifier design written for over 30 years. It introduces the art of valve electronics to the newcomer and provides ready-made practical circuits that will be of great value to enthusiasts and professional audio designers alike. · The practical guide to building, modifying, fault-finding and repairing vacuum tube amplifiers · A hands-on approach to tube electronics - classic and modern - with a minimum of theory · Design, fault-finding, and testing are each illustrated by step-by-step examples · Written by the author of the audiophile cult classic, Valve Amplifiers Morgan Jones's Valve Amplifiers has been widely recognised as the most complete guide to valve amplifier design, modification, analysis, construction and maintenance written for over 30 years. As such it is unique in presenting the essentials of 'hollow-state' electronics and valve amp design for engineers and enthusiasts in the familiar context of current best practice in electronic design, using only currently available components. The author's straightforward approach, using as little maths as possible, and lots of design knowhow, makes this book ideal for those with a limited knowledge of the field as well as being the standard reference text for experts in valve audio and a wider audience of audio engineers facing design challenges involving valves. Morgan Jones takes the reader through each step in the process of design, starting with a brief review of electronic fundamentals relevant to valve amplifiers, simple stages, compound stages, linking stages together, and finally, complete designs. Practical aspects, including safety, are addressed throughout.