Updated: 24 June 2008

• CONTENTS
• Pre and Power Amplifiers in EW
• Power Amplifiers in Elektor
• Power Amplifier Patents in the USA
• My letters to EW NEW

This is a so far incomplete (but growing) collection of the significant EW pre and power amplifier articles. I have given some of them my own rating as to worthiness; if you disagree please let me know. In some cases I wrote down my thoughts on their value... click on Comments.

Most of my articles up to 2004 are now available in one handy volume: Self on Audio

First-rate. Innovative	One of mine. As good as I can make it.	Competent but unexciting	Misleading or pointless	Just plain wrong! Sorry but there it is.
Repeat offenders have colours assigned to their names.

Subject	Author	In issue
30W High-Fidelity Amplifier	Arthur Bailey	.	19
30W Amplifier Modification	Arthur Bailey	.	19
Baxandall
Walker
A New Approach to Class-B	Blomley	.	19
1969
A Simple Class A Amplifier	J. Linsley Hood	Apr	1969
Quasi-Complementary Output Stage Modification	I M Shaw	Jun	1969	p265
1970
15-20W Class AB Audio Amplifier	J. Linsley Hood	June/July	1970
Ultra-low Distortion Class-A Amplifier	L. Nelson-Jones	Mar	1970
1973
Audio Power Amplifier (A+)	P L Taylor	June	1973	p301
1975
A High-Quality Compressor/limiter	Douglas Self	Dec	1975
1976
An Advanced Preamplifier (MRP1)	Douglas Self	Nov	1976
1977
Additions to the Advanced Preamplifier	Douglas Self	Oct	1977
1979
A High-Performance Preamplifier (MRP4)	Douglas Self	Feb	1979
1983
A Precision Preamplifier (MRP10)	Douglas Self	Oct	1983
1984
1985
1986
1987
Crossover Distortion in Class-B amplifiers	Erik Margan	July	1987	p739
Moving-Coil Head Amplifiers	Douglas Self	Dec	1987
1988
Science & Subjectivism: pseudo-science in audio	Douglas Self	July	1988
1989
Feedback & FETs in audio amplifiers	Ivor Brown	Feb	1989	p123
A/AB mosfet power amplifier	John Linsley-Hood	Mar	1989	p261
PSU & protection for for A/AB mosfet power amplifier	John Linsley-Hood	May	1989	p524
Designing Low-noise Audio amplifiers	Wilfried Adam	June	1989
Solid-state Audio power: history.	John Linsley Hood	Nov	1989	p1042
Solid-state Audio power: Blomley, current dumping, Class-S	John Linsley Hood	Dec	1989	p1164
1990
Solid-state Audio power: gain stages.	John Linsley Hood	Jan	1990	p16
Audio power, FETs and feedback.	Ivor Brown	Apr	1990	p343
Audio Preamplifier design 1	John Linsley-Hood	June	1990
Audio Preamplifier design 2	John Linsley-Hood	July	1990
Audio Mixer design	Richard Brice	July	1990
Audio Preamplifier design 3	John Linsley-Hood	Aug	1990
Sound Mosfet Design	Douglas Self	Sep	1990	p760		Comments
Reducing Crossover distortion.	Michael McLoughlin	Oct	1990	p879
Distortion from power supplies	Greg Ball	Dec	1990
1991
Inside Mixing Consoles	Douglas Self	Apr	1991
Digital amplifier developments	Andy Gothard	Jul	1991	p554
Transistor-driven valve amplifier	John Linsley Hood	Aug	1991	p676
Who designed this?	Dr Aubrey Sandman	Sep	1991	p788
1992
Opto-bias for better power amps	Ivor Brown	Feb	1992	p107
200 watt Audio amplifier.	Andrew Hefly	Jun	1992	p454
1993
Integrated Audio amplifier.	John Linsley Hood	Jun	1993	p454
Audio Power Amplifier	Marco Corsi	July	1993	p547
Microprocessor-Controlled audio Preamplifier	Martin Eccles	July	1993
Solid-state Audio Switching	Mike Meechan	July	1993
Audio power chip review.	Ben Duncan	Oct	1993	p804
Distortion In Power Amplifiers: Part 1 of 8	Douglas Self	Aug	1993
1994
Square-Law amplifiers	Michael Williams	Jan	1994	p82
Distortion In Power Amplifiers: Part 8 of 8	Douglas Self	Mar	1994
Common-emitter power amplifiers	Douglas Self	Jul	1994	p548
High speed Audio power.	Douglas Self	Sep	1994	p760
Audio amplifier with feed forward.	Giovanni Stochino	Oct	1994	p818
Better audio from non-complements?	Bengt Olsson	Dec	1994	p988
1995
Ironing out Distortion Part 1	Edward Cherry	Jan	1995	p14
Between amplifier and speaker.	Ivor Brown	Feb	1995	p114
Distortion off the rails	Douglas Self	Mar	1995	p201
Fast power amplifier for audio	Ian Hegglun	Mar	1995	p240
Fets versus bjts	Douglas Self	May	1995	p387
Trimodal audio power: Part 1	Douglas Self	Jun	1995	p462
Trimodal audio power: Part 2	Douglas Self	July	1995	p584
Expert witness: bjts v mosfets	John Linsley-Hood	Aug	1995	p684
Few compliments for non-complements (2-stage power amps)	Douglas Self	Sep	1995	p763
Square law rules in audio power	Ian Hegglun	Sep	1995	p751
1996
Audio power with a new loop	Marcel van de Gevel	Feb	1996	p140
Non-slewing Audio power.	Giovanni Stochino	Mar	1996	p256
Thermal dynamics of power amps: Part1	Douglas Self	May	1996	p410
Thermal dynamics of power amps: Part2	Douglas Self	June	1996	p481
Precision Preamp '96: Part 1	Douglas Self	Jul/Aug	1996
Precision Preamp '96: Part 2	Douglas Self	Sep	1996
Thermal dynamics of power amps Part3	Douglas Self	Oct	1996	p754
Class A power	John Linsley-Hood	Sep	1996	p681
Night Thoughts on Crossover distortion	Douglas Self	Nov	1996	p858
Hybrid power amplifier	Wim de Jager	Nov	1996	p897
1997
Load-invariant audio power	Douglas Self	Jan	1997	p16
Overload Matters (RIAA overload)	Douglas Self	Feb	1997
Ultra fast Audio amplifier. #1	Giovanni Stochino	Apr	1997	p278
Balanced line inputs and outputs: Part 1	Douglas Self	Apr	1997
Balanced line inputs and outputs: Part 2	Douglas Self	May	1997
Error feedback in audio power	William de Bruyn	Jun	1997	p476
Ironing out Distortion Part2	Edward Cherry	Jul	1997	p577
The Audio power interface: Part 1	Douglas Self	Sep	1997	p717
The Audio power interface: Part 2: cables	Douglas Self	Oct	1997
The Audio power interface: Part 3: speakers	Douglas Self	Nov	1997
1998
Diagnosing Distortion (THD residuals)	Douglas Self	Jan	1998	p32
Loudspeaker undercurrents (Otala excess currents)	Douglas Self	Feb	1998	p98
Class B in a new class	Mike J Renardson	Apr	1998	p274
Gain-stage investigations	John Linsley-Hood	Jul	1998	p578
Ultra fast Audio amplifier #2	Giovanni Stochino	Aug	1998	p633
1999
Class A to 300W	Colin Wonfor	Mar	1999	p188		Comments
Class distinction	Douglas Self	Mar	1999	p190
Zero Distortion?	Ian Hickman	Mar	1999	p224
Relay muting	Douglas Self	Jul	1999	p544
Cool audio power: Part 1 (Power Partition Diagrams)	Douglas Self	Aug	1999	p657
Cool audio power: Part 2 (Power Partition Diagrams)	Douglas Self	Sept	1999
Fast audio power	Yuri Ezhkov	Sep	1999	p723
Class A, 32W from a 12V rail	Richard Burfoot	Nov	1999	p934
Audio power analysis	Douglas Self	Dec	1999	p1033
A new Class AB design	Wim de Jager, van Tuy & van der Ven	Dec	1999	p982
2000
Hybrid audio power	Wim de Haan	Mar	2000	p198
Class T Hi-fi?	Ian Hickman	Apr	2000	p274
100W new topology Class B	Russel Breden	June	2000	p486
2001
Letter	Jeff Macauly	Jun	2001	p467
MOSFET power	David White	Aug	2001	p578
Letter	Clive Read	Aug	2001	p637
Coil crosstalk	Douglas Self		2001
Class G: Part 1	Douglas Self	Dec	2001
2002
Class G: Part 2	Douglas Self	Jan	2002
Class G Indicator	Douglas Self	Feb	2002
2003
Amplifier Input Currents	Douglas Self	May	2003
2004
Analogue Switching, Part 1	Douglas Self	Jan	2004
Analogue Switching, Part 2	Douglas Self	Feb	2004
2005
Not a good year for amplifier articles
2006
The Sound of Silence (MC preamps)	Burkhard Vogel	Oct	2006
Class XD: a New Power Amplifier	Douglas Self	Nov	2006	p20

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Amplifier Articles in Elektor: chronological order.

An incomplete guide to power amplifier designs in the European magazine "Elektor".

200W Raw Power	anon	Jan 1981
AXL amplifier	anon	Mar 1985
High-Power AF Amplifier	anon	Jun 1986
LFA-150: A Fast Power Amplifier. Pt 1	A Schmeets	Nov 1988
Medium-Power AF Amplifier	T Giffard	Oct 1990
100W High-End AF Power Amplifier	T Giesberts	Mar 1994
HexFET Amplifier Upgrade	T Giesberts	Sep 1995
300W Power Amplifier	A Riedle	Nov 1995
Compact AF Power Amplifier	T Giesberts	May 1997
.
Pax Error-Correcting Power Amplifier	J Didden	Apr 2008

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US Patents on Audio Amplifiers: chronological order.

An incomplete guide to USA power amplifier patents. It excludes any that are (in my opinion) of no interest, but certainly does not have all of the interesting ones. Anything relating to valves has been ignored; this is the 21st century, after all. Titles have been compressed in some cases.

E =error-correcn

G = Class G

IC = IC tech

Ns =non-switching

P =Protection

McMillan	Multiple Feedback Systems	May 1956	2 748 201
Ketchledge	Distortionless Feedback Amplifier	Jun 1956	2 751 442
Eisenberg	High-Voltage Power Amplifier	Nov 1971	3 622 899	G
Waehner	Multi-Level Power Amplifier	Nov 1973	3 772 606	G
Stanley	High Power Bridge Audio Amplifier	Apr 1974	3 808 545
Takeda et al	Driver Stage of a Class-B Amplifier	Jun 1974	3 821 656
Higuchi	Power Amplifier with Self-Biasing	Feb 1975	3 866 134
Sampei	Amplifier Having Power Supply Voltage Responsive to Input Ampl	Jun 1976	3 961 280
Walker	Distortion-Free Amplifiers	July 1976	3 970 953	E
Pass	Active Bias Circuit for Push-Pull Amplifiers	Nov 1976	3 995 228
Morez et al	Audio Power Amplifier with Automatic Bias Control	Feb 1978	4 077 013
Fukumoto et al	Audio Power Amplifier	May 1978	4 087 761
Pass	Constant-voltage Constant-Current Amplifier	Aug 1978	4 107 619
Stitt	Optically Coupled Bias Circuit	Oct 1978	4 121 168
Lunquist	Audio Amplifier Output Circuit	Mar 1979	4 146 845
Thornton	Eliminating On-Off Transitional Gain Variations	Jul 1979	4 160 216
Odell	Transistorised Power Amplifier	Nov 1979	4 176 323
Kawanabe	Push-Pull Amplifier Circuit.	Jul 1980	4 215 318
Takehara	Audio Power Amplifier	Dec 1980	4 241 313
Kawanabe	Push-Pull Amplifier Circuit.	Mar 1981	4 254 379
Okabe	Single-ended Push-Pull Amplifier	Jun 1981	4 274 059
Iwamatsu	Power Amplifier with Bias Circuit with Temp Compen	Nov 1981	4 302 727
Kondou	Push-Pull Amplifier	Dec 1981	4 306 199
Yamaguchi	Power Amplifier	Feb 1982	4 316 149
Kobayashi	Single-ended Push-Pull Amplifier	Feb 1982	4 317 081
Quilter	Time Delayed Variable Output Current-Limiting	Mar 1982	4 321 554	P
Shibata et al	Bias Circuit for Power Amplifier	May 1982	4 331 930
Otao	Power Amplifier Circuitry	Jun 1982	4 334 197
Tamura	Power Amplifier Circuitry	Aug 1982	4 342 966		R
Amada et al	Audio Frequency Power Amplifier Circuit	Aug 1982	4 345 215
Iwamatsu	Class-A Push-Pull Amplifier with Bias Control	Oct 1982	4 356 452
Tanaka	Distortion Correction Circuit for A Power Amplifier	Jan 1983	4 367 442	E
Tanaka	Bias Circuit for Use In Push-Pull Circuit	Aug 1983	4 401 951	Ns	R	S
Suzuki	Power Amplifier	Aug 1983	4 401 954
Muller	Biasing Circuit for MOSFET Power Amplifiers	Sep 1983	4 403 198
Gross	Audio Power Amplifier	Nov 1983	4 415 868
Suzuki	Single-ended Push-Pull Amplifier With Two PushPull	Dec 1983	4 422 050		R	S
Velazquez	Audio Power Amplifier	Aug 1984	4 464 634 Low
Strickland	Distortion-Free Complemented Error-Feedback Amplifier	Oct 1984	4 467 288	E
Iwamatsu	Amplifier With Distortion Cancellation	Oct 1984	4 476 442	E
Nijman et al	Amplifier Circuit	Nov 1984	4 484 151
Ishikazi	Power Amplifier	Dec 1984	4 489 283		R
Main et al	Bias Circuit Independent of Device Characteristics	Jan 1985	4 491 804		R
Gunderson	Output Following Intermediate Cascode Circuit	Apr 1985	4 511 857
Nakayama	Emitter-Follower Type Single-Ended Push-Pull Circuit.	May 1985	4 520 323
Nakayama	Emitter-Follower Type Single-Ended Push-Pull Circuit.	Dec 1985	4 558 288
Nakayama	Emitter-Follower Type Single-Ended Push-Pull Circuit.	Jun 1986	4 595 883	Ns	R	S
van Tuijl	Push-Pull Amplifier with Stable Class AB Operation	Aug 1986	4 607 233
Dijkmans et al	High Efficiency Low Distortion Amplifier	Aug 1987	4 688 001	G
Wingate	Audio Power Amplifier	Aug 1987	4 688 002
LaRosa et al	Class-G Bridge Amplifier with Unipolar Supplies	Jan 1988	4 721 919
Pass	Opto-isolated Bias Circuit for Push-Pull Power Amplifiers	Jun 1988	4 752 745
Verhoeven et al	Bridge Amplifier	Jul 1988	4 758 796
Botti	Integratable Class-AB Output Stage	Mar 1989	4 814 723		R
Botti	So-Called Bridge Audio Amplifier	May 1990	4 922 207		R
Susak et al	Amplifier Output Stage	Feb 1991	4 990 863	IC
Deaver	Automatically Biasing a Push-Pull Amplifier	Feb 1991	4 991 916
Greame et al	Adaptive Bias Circuit for Preventing Turnoff	May 1991	5 019 789
Chater	Bias Control for Power Amplifiers	Oct 1991	5 055 797
Landi	High-Efficiency Class-A Amplifier	Oct 1991	5 057 790	Ns	R	S
Padi	Working Point Adjusting Circuit for a Power Amplifier	Dec 1991	5 070 308		R	S
Alexander	Current Feedback Audio Amplifier	Mar 1992	5 097 223
Waller	Audio Power Amplifier with Reactance Simulation	Dec 1993	5 268 527
Dijkmans	Amplifier Having Temperature Compensated Bias	Aug 1994	5 337 012
Pass	Efficient High Fidelity Audio Power Amplifier	Aug 1994	5 343 166
Sondermeyer	High Efficiency Amplifier with Reduced Switching Distortion	Feb 1995	5 387 876	G
Pass	Amplifier Having an Active Current Source	Jan 1998	5 710 522
Candy	Amplifier Having Ultra-Low Distortion	Apr 1999	5 892 398	E
Huijser	High Gain Low Distortion Bridge Amplifier with Feedback	May 1999	5 903 189
Seven	High Power Output Stage with Temperature Stable Iq	Oct 1999	5 973 563
Reffay	Power Amplifier Device	Jan 2000	6 016 079
French et al	Derived Power Supply for Composite Bridge Amplifiers	Dec 2000	6 160 455
Servaes et al	Power Amplifier Arrangement	Apr 2001	6 215 356	G
Close	High Current OpAmp Output Stage	Jul 2001	6 262 633	IC
Barbetta	Wide Bandwidth MOSFET Power Amplifier	Jul 2001	6 268 770

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