ВУЗ: Казахская Национальная Академия Искусств им. Т. Жургенова
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Synopsis
Chapter 1 Introduction and general survey
The economic importance of audio amplifiers
There are no practical textbooks
Knowledge assumed
Origins and aims
The study of amplifier design
Some new findings in amplifier design
A snapshot of the technology
No inspiration from IC technology
Aimed at discrete amplifiers
Amplifiers are now designable
Misinformation in audio
Science and subjectivism
The Subjectivist position
A short history of subjectivism
The limits of hearing
Articles of faith: the tenets of subjectivism
The length of the audio chain
The implications
The reasons why
The outlook
Technical errors
The performance requirements for amplifiers
Safety
Reliability
Power output and load capability
Frequency response
Noise
Distortion
Damping factor
Absolute phase
Acronyms
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Synopsis
Chapter 2 History, architecture and negative
feedback
A Brief History of Power Amplifiers
Power amplifier architectures
The three-stage structure
The two-stage amplifier structure
Power amplification classes
Class-A
Class-AB
Class-B
Class-C
Class-D
Class-E
Class-F
Class-G
Class-H
Class-S
Variations on Class-B
AC and DC coupled amplifiers
The advantages of AC-coupling
The advantages of DC-coupling
Negative feedback in power amplifiers
Some common misconceptions about negative feedback
Amplifier stability and NFB
Maximising the NFB factor
Linearising before adding NFB
Chapter 3 The general principles of power
amplifiers
How a generic power amplifier really works
The advantages of the conventional
The eight distortions
The performance of a standard power amplifier
Determining open-loop non-linearity
Direct open-loop gain measurement
The use of ‘model’ amplifiers
The concept of the Blameless amplifier
Chapter 4 The small signal stages
The role of the input stage
Three kinds of differential input stage
BJTs versus FETs for input stages
Singleton versus differential input stages
Measuring input stage distortion in isolation
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Synopsis
Importance of input stage balance
Use of current-mirrors
Constant-gm degeneration
Radical methods of improving linearity
Input stage cascoding
Input noise and how to reduce it
Input balance and DC offset
The input stage and the slew-rate
The voltage-amplifier stage
Measuring VAS distortion in isolation
VAS operation
VAS distortion
Linearising the VAS: active-load techniques
Enhancements to the basic VAS
The importance of voltage drive
The Balanced VAS
The VAS and the manipulation of open-Loop bandwidth
Manipulating open-loop bandwidth
Conclusions
Chapter 5 The output stage I
Classes and devices
The distortions of the output
Harmonic generation by crossover distortion
Comparing output stages
The Emitter-Follower output configuration
The Complementary-Feedback-Pair output configuration
Quasi-Complementary output stages
Output triples
Triple EF output stages
Distortion and its mechanisms
Large-signal distortion
The load-invariant concept
The LSN mechanism
Doubled output devices
Better output devices
Feedforward diodes
Trouble with triples
Loads below 4 !
Better 8-! performance
A practical load-invariant design
The latest findings
Summary
Crossover distortion
Switchoff distortion
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Synopsis
Thermal distortion: why it doesn’t exist
Thermal distortion in a power amp IC
Selecting the appropriate output stage
Closing the loop: distortion in complete amplifiers
Conclusions
Chapter 6 The output stage II
Distortion 4: non-linear loading of the VAS
Distortion 5: incorrect decouple grounding
Distortion 6: the induction of non-linear currents
Distortion 7: incorrect feedback connection point
Distortion 8: feedback capacitor distortion
A complete Class-B power amplifier
Chapter 7 Compensation, slew-rate, and stability
Compensation in general
Dominant-pole compensation
Lag compensation
Including the output-stage: inclusive Miller compensation
Nested feedback loops
Two-pole compensation
Output networks
Amplifier output impedance
Minimising amplifier output impedance
Zobel networks
Output inductors
The output inductor value
Cable effects
Crosstalk in amplifier output inductors
Conclusions
Reactive loads and speaker simulation
Resistive loads
Loudspeaker load modelling
Reactive and loudspeaker loads
Single-speaker load
Two-way speaker loads
Enhanced loudspeaker currents
Amplifier instability
HF instability
LF instability
Speed and slew-rate in audio amplifiers
The basics of amplifer slew-limiting
Slew-rate measurement techniques
Improving the slew-rate
Simulating slew-limiting
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