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All Material Copyright © 1998-2019 Rod Elliott (ESP)
Copyright For Each Individual Article Is Shown At The End Of Each Page
Page Last Updated - May 2019

Main Index
Articles Index
Projects Index

555 Timer Applications
Active Filters
Active Vs. Passive Crossovers
A-B Blind Comparator
ABX Test Set
Acoustic Feedback & Frequency Shifting
Active Filters Using Gyrators
AM Radio - Wideband/ Hi-Fi
Amplitude Modulation For Simulations
Amplifier Basics - Intro
Amplifier Basics - Part 1
Amplifier Basics - Part 2
Amplifier Basics - Part 3
Amplifier Basics - Part 4
Amplifier Basics - Part 5
Amplifier Basics - Part 6
Amplifier Bridging
Amplifier Classes - Class-A, Class-B, etc.
Amplifier Design
Amplifier Efficiency
Amplifier Troubleshooting
Amplifier Troubleshooting - Part 2
Amplifier Protection
Amplifier Sound
Analogue Vs. Digital

Baffle Step EQ
Balanced Circuits
Beginners Guide to Components
Bi-Amplification (Part I)
Bi-Amplification (Part II)
BJT Parameters
Bucking Transformers
Bulletin Boards
Buying Electronic Components

Cables - Part 1
Cables - Part 2
Cables - Part 3
Cables - Part 4
Cables - Part 5
Cables - Part 6
Cable Impedance
Cable Information
Capacitors in Depth
Commercial Sound (70-100V Lines)
Compound (Sziklai) Vs. Darlington pairs
Comparators - The Unsung Heroes Of Electronics
Coupling Capacitors
COAX - Introduction To Coaxial Cables
Current Drive Power Amps & Effects on Speaker Drivers

Class-A Amplifiers
Class-A Amplifiers - Part 2
Class-D Amplifier Theory & Design
Class-G Amplifiers
Compliance Scaling Loudspeakers
Compression in Audio
Counterfeit Transistors
Current Sources, Sinks & Mirrors

Derived (Subtractive) Crossover Networks
Designing with Opamps - Part 1
Designing with Opamps - Part 2
Designing with Opamps - Part 3
Distortion & Negative Feedback
Doppler distortion in Loudspeakers
DSP - Digital Signal Processing in Audio

Earthing (Grounding) Techniques
Electret Microphones, Powering & Uses
Electronics Tools
Electrocution & How To Avoid It
Electrocution & How To Avoid It
Equalisation & How It Works
External Power Supplies - New Regulations

Followers & Buffers, Various Techniques Examined
Frequency, Amplitude and dB
Fusing & Circuit Protection

Glossary of Terms
Guitar Amps - Repair or Replace
Guitar Speakers - Getting 'the sound'

Heatsink - ESP Extrusion
Heatsinks - DIY
HEXFET Audio Amplifiers
High Speed Opamps

IC Power Amplifiers - more power by adding transistors
Impedance Effects
Instrument Amplifiers
Intermodulation Distortion - sum & difference frequencies
Intermodulation Distortion - measurement techniques & effects
Incandescent Lamp Ban
Inrush Current Mitigation
Introduction to Potentiometers
Inverters - different types explained

JLL Hood Class-A Amp
Linkwitz Transform
LDO (Low Dropout) Voltage Regulators
Lithium Cell Charging & Battery Management
Loudspeaker Power vs. Efficiency

Mains Power Quality
Mains Safety (Essential Reading)
Meters, Multipliers & Shunts
Microphone Signal Splitters
Miscellaneous Components
Mixing Principles, Active & Passive
Morse Code
Myths in Audio

Negative Impedance
Noise in Audio Circuits
Neville Thiele Method (NTM™) Crossovers

Opamp Alternative Circuits
Oscilloscopes. How They Work And Usage

Passive Crossovers
Patents - General Information
Phase Angle Vs. Transistor Dissipation
Phase Correction - Myth or Magic?
Phase, Time & Distortion
Power Amplifier Clipping Behaviour
Power Ratings
Power Supply Design
Power Supply Snubbers

Relays - Part 1
Relays - Part 2
Reverberation Tanks
Review of BE Valve Amplifier

Satellites & Subs (QB5 Alignment)
Safe Operating Area (SOA)
(The) Subwoofer Conundrum
Series vs. Parallel Crossovers
Small Satellite Speaker (Part 1)
Small Satellite Speaker (Part 2)
Small Satellite Speaker (Part 3)
Soft Start Circuits
Sound Impairment Monitor
Sound - Illusion?
Speaker Failure
Speaker Failure
State of Manufacture

Thiele-Small Parameters
Transistor Matching
Transistor listing
Transformers - Part 1
Transformers - Part 2
Transformers - Part 3
Transformers - Part 4
Transformers - The Variac
Transformers for 'Line Level' Audio
Triamped Speaker System - Part 1
Triamped Speaker System - Part 2

Voltage Dividers & Attenuators
Volume Filling Reflex Enclosures

What Makes Tweeters Blow
What Is Hi-Fi
Why Do It Yourself?
Wiring A Power Supply
Waveguides, Part 1
Waveguides, Part 2
Waveguides, Part 3

Valve Articles Index
Valve Amps - Do they really sound different?
Valve intro - types, terminology, etc.
Bias and Gain
Valve Stage Analysis
Design Considerations - Part 1
Design Considerations - Part 2
Low Distortion Preamps
Valve Myths
High Voltage DC Supply
High Voltage Time Delay

Application Notes
Application Notes Index
Precision Rectifiers
Analogue Metering Amplifiers
High Power Led SMPS
Car Dome Light Extender
Zero Crossing Detectors
Ultra-Simple SMPS
Transistor Assisted Zener
Using Zener Diodes
DC Motor Speed Controller
DC Motor Speed Controller (II)
2-Wire/4-Wire Converters

Ordering Info
Price List
Order Form
Encrypted Order Program
Downloadable price file for above
Fully Built Modules
Class-D amplifier
Guitar Amp Module
Digital Flash Module
VP-103 Valve Preamp
PCB Catalogue (HTML)
Paymate Details
PayPal Details
Western Union Details
Dead Letters

Clock Components
Clock Motors
Kundo Battery Clocks
Old Synchronous Motors
Frequency Changer
Build a Synchronous Clock
Free Pendulum Clock
1.5V Mains Supply
Magnet Charger
Simple Flux Meter
Spark Quench Circuits
1 second timebase
Fast Demagnetiser

L-R Crossover (2)
Reader Feedback - Part 1
Reader Feedback - Part 2

Download Index
Encrypted Order Form (ZIP)
Semiconductor Data (EXE)
Heatsink Calculator (ZIP)
MFB Filter Calculator (EXE)
Help Kill Spam (ZIP)
LED VU Design (ZIP)
Loudspeaker Parameters (ZIP)
Crossover Design (ZIP)
Linkwitz Transform Design (ZIP)
Reminder Program (EXE)
Stores Program (ZIP)
PC Timer Program (EXE)
Crossover Calculator (EXE)
Heatsink Design (XLS)
Transformer analysis program (ZIP)
Transformer analysis spreadsheet (ZIP)
Transformer design program (ZIP)
World Time Clock (EXE)

Humour Index
Humour - Part 1
Humour - Part 2
Murphy's Laws
A Space Oddity
If Your O/S Were an Airline
Waltzing Matilda Explained
Monty Python
Dynamic Range Vs, Ambient Noise
Satcure Products

Hall of Shame
Home Page
Main Index
Main Links Page
Mad As Hell - Part 1
Mad As Hell - Part 2
Mad As Hell - Part 3
Mad As Hell - Part 4
ESP Ethics Policy
About ESP Site
Contact the Author
Submit Your Material
Contracting Details
About the Author
Custom Projects for Education
Frequently Asked Questions
Spam, Scams & Security
Scams - how they work
Your on-line security
Spam, Spam, Spam, Spam
Search Page
Contribute Project/ Article

TCAAS (The Class-A Amplifier Site)
The JLH Class-A Amplifier
Other JLH Amplifier Designs
Other Class-A Amplifiers
Classic Class-B Schematics
JLH Power Amp Schematics
The Published Articles of John Linsley Hood

Lamps, PSUs, Energy
Lamps - Incandescent, etc.
Capacitance, Inductance & Non-Linear Loads
Dimmers - Part 2
Dimmers With LED Lighting
Electronic Transformers
ESL (Electron Stimulated Luminescence) Lamps
External Power Supplies
Fluorescent Lamps
Induction Fluorescent Lamps
Inrush Current Protection
LED Lighting
LED Lighting - Thermal Design
Sulphur Plasma Lamps
Power Calculations - Watts, VA (AC or DC)
Power Factor Correction
Power Saver Scam
Wind Turbine Introduction
Wind Turbine Noise

Projects Index
Projects Index by Category
Project List in Numerical Order

01 Better Volume Control
02 Simple Preamp
02 60W Power Amp
04 Power Amp Supply
05 Preamp Power Supply
05A Updated Preamp Power Supply
06 Phono Preamp
07 Discrete Opamp
08 3rd Order Electronic Crossover
09 Linkwitz-Riley Crossover

10 Class-A Amplifier
11 Pink Noise Generator
12 Current Feedback Power Amp
12A El-Cheapo Power Amp
13 Low Noise Preamp
14 Power Amp Bridging
15 Capacitance Multiplier
16 Audio Millivoltmeter
17 A-Weighting Filter
18 Surround Decoder
19 50W IC Power Amp

20 Simple Bridge Adaptor
21 Stereo Width Controllers
22 Audio Oscillator
23 Clipping Indicator
24 Headphone Amplifier
25 Phono Preamps For All
26 Digital Delay
26A PT2399 Digital Delay
27 Guitar Amp (Original)
27 Guitar Amp (Part 1)
27 Guitar Amp (Part 2)
28 Quasi-Parametric EQ
29 Tremolo Unit

30 Mixing Desk (Part 1)
30 Mixing Desk (Part 2)
30 Mixing Desk (Part 3)
30 Mixing Desk (Part 4)
30 Mixing Desk (Part 5)
31 Transistor Tester
32 Car Audio Preamp
33 Speaker Protection and Mute
34 Spring Reverb Unit
35 Direct Injection Box
36 DoZ Class-A Amplifier
37 DoZ Preamp
38 Auto Power-On
39 Soft Start Power Switch
3A 60W Hi-Fi Power Amp
3B 25W Class-A Power Amp

40 Load Sensing Auto Switch
41 Opamp Design & Test Board
42 Thermo-Fan Controller
43 Simple DC Split Supply
44 Dual Lab Supply
45 Bass Compressor
46 Thermal Shutdown
47 VOX AC30 Simulator (withdrawn)
48 Sub Equaliser
49 Guitar Vibrato

50 Mic Circuit Tester
51 Balanced Line Drivers
52 Distortion Analyser
53 Power Limiter
54 Low Power FM Transmitter
55 PPM and VU Meters
56 Variable Amp Impedance
57 Sound Impairment Monitor
57 Speaker Measurement Set
59 Self Oscillating Amp

60 LED VU Meter
61 (Withdrawn)
62 Lighting System (Part 1)
62 Lighting System (Part 2)
62 Lighting System (Part 3)
62 Lighting System (Part 4)
62 Lighting System (Part 5)
62 Lighting System (Part 6)
63 MFB Filter
64 Instrument Graphic EQ
65 Strobe Light
66 Balanced Mic Preamp
67 Audio Peak Limiter
68 Sub Power Amp
69 Low power +/-12V supply

70 DoZ Headphone Amp
71 Linkwitz Transform Circuit
72 20W IC Stereo Amp
73 PC Sound System
74 RF Probe
75 Constant Q Graphic EQ
76 Opamp Based Power Amp
77 High Current 13,8V Supply
78 2nd Order Electronic Crossover
79 Current Sense Power Switch

80 Reverse RIAA Equaliser
81 12dB L-R Crossover
82 Loudspeaker Test Box
83 MOSFET Follower Amplifier
84 1/3 Octave Sub Equaliser
86 Mini Audio Oscillator
87 Balanced Transmitters & Receivers
88 Audio Preamp
89 Car Switchmode Supply

90 Dimmer Polarity Reversal
91 78RPM Phono EQ
92 Guitar and Bass Sustain
93 Recording & Measuring Mic
94 Universal Preamp Mixer
95 Low Power -VE Supply
96 48V Phantom Supply
97 Hi-Fi Preamp
98 Auto Charger for Battery Hi-Fi
99 36dB/ Octave Subsonic Filter

100 Headphone Adaptor for Amplifiers
101 200W MOSFET Power Amplifier
102 Simple Pre-Regulator
103 Subwoofer Phase Control
104 Preamp/ Crossover Mute Circuit
105 Build an Electrostatic Loudspeaker (ESL)
105-2 Electrostatic Loudspeaker - Part 2
105-3 Electrostatic Loudspeaker - Part 3
106 hFE Tester for Transistors
107 Phase / Polarity Reversal Switching
108 Switchmode PSU Protection
109 Headphone Amp

110 IR Remote Control
111 PIC Speaker Protection
112 Dummy Head Microphone
113 Hi-Fi Headphone Amp
114 Class-D (PWM) Power Amp
115 GainClone Amplifier (Part 1)
115 GainClone Amplifier (Part 2)
116 Class-D Subwoofer Amp
117 1.5kW Power Amplifier
118 Ultra Simple PC Peripheral Switch
119 Component Signature Analyser

120 Crowbar Speaker Protection
121 Reading Inductance
122 Ultra-Simple Mic Preamp
123 18dB/Octave Crossover
124 Dummy Load
125 4-Way 24dB/Octave Crossover
126 10A, 12V PWM dimmer/ speed controller
127 Two Channel TDA7293 power amplifier
128 Analogue VU Meter Bridge
129 Matrix Mixer

130 Inverse A-Weighting Filter
131 Light Activated Switch
132 Air Bearing Tonearm
133 PA-PC Audio Interfaces
134 4mA Current Loop Microphone
135 Phase Correlation Meter
136 Real-Time Audio Analyser
137 Bi-amped PA Amplifier
138 Mains Over/ Under Voltage Cutout
139 Mains Current Monitor
139a Simple Current Monitor

140 True RMS Adaptor
141 VCA Based Preamplifier (THAT2180)
142 Simple High Current Regulator
143 Tone Burst Generator/ Gate
144 Mains Power Sequencer
145 Silent Guitar Effects Switching
146 Overload/ Clipping Indicator
147 BJT Muting Switch
148 State Variable Crossover
149 Musical Instrument Graphic EQ

150 Wien Bridge based equaliser
151 High Voltage DC Supply
152 Bass Guitar Amplifier - Part 1
152 Bass Guitar Amplifier - Part 2
153 Frequency 'Isolator' EQ
154 PC Oscilloscope Interface
155 Variable High And Low Pass Filters
156 12V Trigger Switches
157 3-Wire trailing-edge light dimmer
158 Low-Noise Test Preamplifier
159 3-Wire Leading-Edge Dimmer

160 LM386, LM380 & LM384 Power Amplifiers
161 High Impedance Input Stages
162 Voltage Controlled Oscillator
163 Preamp Input Switching Using Relays
164 Signal Tracer
165 Valve Tester for Service Techs
166 Push-on, Push-off Mains Switch
167 MOSFET Follower & Circuit Protection
168 Low Ohms Meter
169 Battery Powered 'Audiophile' Amplifier

170 6dB/ Octave Active Crossover
171 Infrasound Translator
172 Wattmeter for AC Power Measurements
173 Constant Directivity Horn Equaliser
174 Ultra-Low Distortion Oscillator
175 Single Supply BTL Amp DC Protection
176 Fully Differential Amplifier
177 Constant Current Transistor Tester
178 Low Voltage Power Amplifier
179 Filament Lamp Stabilised Wien Bridge Oscillator

180 Amplifier 'Power Meter'
181 Audio Accelerometer
182 Maximum Length Sequence (MLS) Noise Generator
183 Signal Detecting Audio Ducking Unit
184 Li-Ion Battery Cutoff For Electronics Projects
185 Speaker, Microphone & Circuit Polarity Tester
186 Workbench Test Amplifier
187 Moving Coil Head Amplifier

ABX ABX Comparator
X      A-B Switch Box

Project Suggestions

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