The Audio Pages

Page Last Updated - 01 July 2008

	Feature Articles	Updated
	Incandescent Lamps - Should they be banned? Really? This is rapidly becoming a topic (pardon the pun)	05 May 07
	External PSUs - Hot on the heels of the CFL fiasco, now the leglislators want to ban external transformer supplies	05 May 07
	Benefits of Bi-Amplification - Not quite magic, but close (Part I)	02 May 05
	Benefits of Bi-Amplification - Crossovers, tri-amping, etc. (Part II)	02 May 05
	Counterfeit (Fake!) Semiconductors - Don't you be caught with fake, below spec transistors when you build a project!	01 Jul 08
	Education - Customised projects for schools, technical colleges and universities	30 Apr 03
	The State of Manufacturing - This article should be a mandatory read for all businessmen and politicians, a real wake-up call !	03 Sep 02
	Amplification
	Amplifier Sound - What causes the perceived differences between amps?  Is it real or imaginary?	09 Apr 00
	Class- A - a discussion of the benefits of Class-A amplifiers	02 Apr 05
	Clipping Behaviour - One of the lesser known effects of amplifier clipping, and the damage it can do.	15 Oct 04
	Distortion & Negative Feedback - A detailed look at the way negative feedback reduces distortion	17 Oct 06
	Musical Instrument Amplifiers - Guitar, Bass and Keyboard	04 Feb 01
	Short Circuit Protection - Testing amplifiers to the limits ‡	22 Aug 00
	Soft Clipping - Is adding a soft-clip circuit worth the effort?	15 Apr 06
	The Need For Speed - Very high speed opamps from Texas Instruments	17 Aug 01
	Phase Angle Vs. Transistor Dissipation - A simplified approach to understanding Safe Operating Area	19 Mar 05
	PWM Amplifiers - Theory and design concepts behind these 'new' amplifiers	25 Jun 05
	Sound Impairment Monitor - Is This The Answer? - A new method to monitor distortion in real time	23 Sep 00
	Transistor Safe Operating Area - What is SOA, and how does it affect amplifier designs	14 Aug 03
	Valve Amplifiers - do they really sound different - Includes a review of one of my valve amps	28 Nov 99
	Cables
	The Truth About Cables, Interconnects and Audio in General - A "must read" article	20 Sep 02
	More Truth About Cables - A white paper discussing speaker cables and interconnects *‡	22 Jul 01
	Cable Impedance - Characteristic impedance, high capacitance designs and amp stability	17 Oct 03
	General Information
	A-B Switch Box for Amplifier Comparisons - Something to offend everyone, or a great tool? ‡	15 Aug 00
	ABX Comparator - A true ABX system that does not need a PC or microcontroller ‡	11 Aug 02
	AM Radio - Approaches to high fidelity AM broadcast band reception ‡	18 Feb 06
	Capacitors - What are the influences that determine the so-called 'sound' of capacitors. Covers dielectrics, dissipation factor, etc.	25 Oct 05
	CD, SACD and DVD-A -A Comparison of the formats in a discussion between Niklas Ladberg and Ing. Öhman (very interesting) ‡	28 Aug 02
	Compression In Audio - Ever wondered why some music sounds flat and lifeless, even though it's loud?	21 Dec 01
	Earthing Your Hi-Fi - Tricks and Techniques - How to eliminate hum without affecting safety	30 Dec 99
	Electrocution - How to avoid being electrocuted, what to do if the worst happens	28 Apr 07
	DC Offset and Transformers - Many people have found that toroidal transformers growl at times. This explains why, & how to fix it.	09 Mar 08
	Build Your Own Heatsink? - Yes, it can be done. If you have the tools, you can make a heatsink as big as you'll ever want.	11 Feb 06
	Impedance - What does it really mean?  A general discussion on impedance, damping, etc.	24 Jan 05
	Microphones - An introduction to the different types, polar response and behaviour of microphones	12 Jan 06
	Why Do Tweeters Blow? - The real reason that tweeters (and other drivers) are destroyed by distortion	28 Jul 01
	What is Hi-Fi - A contributed article on some of the subtle aspects of Hi-Fi ‡	05 May 01
	What is Hi-Fi (Part II) - Continuation of 'What is Hi-Fi' explaining the idea of accuracy (amongst other things)	29 Mar 04
	Beginners' Luck - The beginners' Guide to ...
	Electronics Basics - The Lenard Audio site has an education section that is highly recommended for those just starting out
	Amplifier Basics - How Amps Work - How amplifiers do what they do	06 Apr 05
	Amplifier Efficiency - Power Loss, DC voltages and current explained	29 Jan 00
	Amplifier Troubleshooting and Repair Guide  If it's broken, you may be able to fix it. This article is designed for those new to repairs	27 Apr 03
	Amp Troubleshooting and Repair Guide - Part 2  Preamps, crossovers and other opamp circuits can cause grief too	06 Jan 07
	Bridging - How the "Trimode" bridging system works in car power amplifiers	20 Oct 02
	Bulletin Boards - A guide to etiquette when posting at your favourite forum ‡	09 Apr 01
	Designing With Opamps I - What they are, what they do, and how they do it	03 May 00
	Designing With Opamps II - Audio applications, filters, crossovers, etc.	08 May 00
	Designing With Opamps III - More Filters, Specifications, Comparators, etc.	11 May 06
	Electronics - Part 1  Passive components - resistors, capacitors and inductors explained	13 Mar 01
	Electronics - Part 2  The resistor 'E' series (e.g. E12, E24, etc), Zener Diodes	05 Mar 04
	Frequency, Amplitude and dB - An explanation of the terms, what they mean, and how they are applied	02 Dec 06
	Meters, Multipliers & Shunts - How to use analogue and digital panel meters	06 May 06
	Potentiometers.  - what they are and how to use them in practical circuits.	22 Jan 03
	Power - An explanation of the derivation of PMPO in amplifiers.  Light reading, really	19 Jun 00
	Tools - The first in a series on mechanical aspects of your hobby ‡	21 Mar 01
	Voltage Dividers & Attenuators - A short article describing how to design these essential circuits	21 Dec 02
	Design Guidelines
	Amplifier Design - ESP's contribution to the everlasting debate	09 Jun 01
	Amplifier Design With HEXFETs - Getting good performance from vertical MOSFETs is possible (Updated)	13 Mar 06
	Balanced Driver with Floating Output - An in depth discussion of the design process ‡	14 Apr 02
	Current Sources, Sinks & Mirrors - A discussion on these much misunderstood circuits.	28 Apr 07
	Heatsinks - An article on heatsink selection, transistor mounting and thermal transfer principles	17 Sep 03
	Noise in Audio Amplifiers - An explanation of noise figures, and how circuit noise is calculated	29 Jan 00
	Opamp Alternatives - A sample of the circuits that were in common use before opamps 'took over'	28 Apr 05
	Power Supply Design - How to design linear power supplies - transformers, rectifiers and filters	03 Dec 07
	Transistor Matching Tests - Matching Bipolars or MOSFETs for critical amplifier applications	08 Dec 01
	Variable Impedance Amplifiers - How you can control the output impedance of a power amp	22 Apr 00
	Power Supplies
	Power Supply Wiring  There are a lot of considerations for the wiring of a PSU - read about it here	07 Jun 03
	Transformers - Part 1  The basics of transformers, what they do, and how they do it.	05 May 01
	Transformers - Part 2  The details of magnetic circuits, windings, core types and losses	03 Apr 01
	Transformers - Part 3  Designing and analysing transformers - not at all for the faint-hearted, but all very useful information.	16 Jan 06
	Small Power Supplies  Design of small PSUs - includes information that might save your life !	12 May 08
	Crossovers, Filters and Signal Processing
	Active Vs. Passive Crossovers - An explanation for the profound audible differences	11 Jan 04
	Baffle Step Compensation - What it is and why we need to compensate for it	08 Dec 01
	Derived (Subtractive) Crossovers - An examination of these networks, and why they are unsuitable for serious use	21 Sep 05
	Digital Signal Processing (DSP) - What DSPs can - and cannot - do for your system	09 Dec 06
	NTM™ Crossovers - This is a topic that has virtually zero technical information on the Net ... until now.	15 Sep 05
	Passive Crossovers - The Design of High Quality Passive Crossover Networks	05 Nov 01
	Phase Correction - Myth or Magic? - Do all-pass filters really work to correct loudspeaker phase anomalies?	27 May 07
	Serial vs. Parallel Crossover Networks - Are there any real differences?	14 Aug 03
	Loudspeaker Design
	Compliance Scaling - Fitting just about any driver to just about any alignment	30 Jun 05
	Doppler Distortion in Loudspeakers - Is the effect real or imaginary when applied to loudspeakers?  The results may surprise you	23 Aug 04
	Impedance - Effects Of Source Impedance on Loudspeaker Drivers	22 Jul 01
	The Linkwitz Transform Circuit - What it is, what it does and how it does it ‡	16 Sep 02
	Loudspeaker Power vs. Efficiency - There's more to this than meets the eye	16 Dec 06
	Loudspeakers (Part I) - see the production of my latest triamped speaker boxes unfold	14 Jul 01
	Loudspeakers (Part II) - The electronics that drive the 3-way system are described	18 Nov 01
	Phase, Time and Distortion in Loudspeakers - Is "Time Alignment" worth the effort?	30 Jul 02
	Pikku 9 - Simple Network Lowers f3 - A useful approach for obtaining better bass from a very small loudspeaker ‡	23 Jul 06
	Satellites & Subwoofers - Description of the little known QB5 loudspeaker alignment.  Maximum SPL from 2-way bookshelf speakers. ‡	28 Aug 04
	Small Satellite Loudspeaker - Using techniques described in various articles, this project should have wide appeal for home theatre ‡	27 May 07
	Subwoofer Conundrum - Some tips and hints on subwoofer selection, efficiency and placement	12 Mar 04
	Thiele Small Parameters - Determining the Thiele/Small parameters for a loudspeaker driver	12 Jan 06
	Volume Filling a Reflex Box - It is generally thought that vented boxes should not be filled, but this isn't necessarily the case ‡	05 Feb 07
	Practical DIY Waveguides - Waveguide definition, calculation and construction ‡	01 Dec 06

	The article is new - that must come as a surprise   Less than 2 months old (typically).
RED	Dates in the update column indicate a new or updated (within 2 months) article. Usually accompanied by
	Indicates an article that may include humour - caution is advised
‡	Contributed article (see copyright notice on article page)

I must express my great appreciation to Geoff Moss from the UK, who has provided me with information about spelling errors, inconsistencies, and general errors in many of these articles. Geoff has done the thing that I cannot do - looked at the articles with detachment, and has spotted and brought to my attention several howling blunders as well as the general editorial help.

Geoff, my sincere thanks and appreciation for what has been many hours of work. This short acknowledgement is scant reward, but I really appreciate the help and assistance.

In addition, I would like to thank the many readers who have pointed out various additional errors and omissions - Your help in ensuring that the information on these pages is as accurate as possible is appreciated, always!

Although it goes without saying (but I will say it anyway :-) the contributed articles and projects from all over the world have added considerably to the overall value and range of topics covered in these pages, and on behalf of all the readers of The Audio Pages, I thank you for you efforts. Writing a clear and descriptive technical article is not an easy task, but your perseverance is acknowledged, and I am grateful that you have taken the time to share your knowledge.

May the flow of input continue - for anyone who would like to contribute, please do not hesitate to contact me.

At any given time, there are usually articles in production either by myself or contributors. It is no longer possible (or sensible) to leave hints as to what may or may not be coming, since it is so easy to get sidetracked by something new that comes along. Feel free to offer suggestions, or offer your own contribution.

Last significant page update 11 Feb 2006 - rearranged each section into alphabetical order, added DIY heatsinks