DIY-Audio Articles:
Assorted articles relating to audio

• Hi-Fi Amplifiers for beginners - What are the basic building blocks inside a typical amplifier?
• Introduction to Gainclones - Read this to learn about the latest craze in DIY-Audio.
• Op-Amps for beginners - what is an op-amp, and how do you use them?
• Power supply basics - an introduction to power supplies for audio.

Workshop Conversion:
This was the first priority!

• Planning - deciding how to use the space
• Phase 1 - the initial work to form the basic space
• Phase 2 - subsequent work to make improve the workshop
• Front Area - the space left at the front of the garage.
• Workshop Tour - September 2000 - showing the garage after Phase 1.
• Workshop Tour - July 2004 - a new tour made before we sold our house.

A4 Power Amp:
A four-channel amplifier using the LM4780, offering bridged and bi-amp modes.

• Overview - Introduction to the amplifier.
• Analogue circuit design - Implementing the LM4780.
• Control circuits - The PIC-based control system.
• Power supply - Details of the custom-made torroid and the power supply.
• Construction - Building the the enclosure from "recycled" materials.
• Conclusions - So far I'm impressed!
• Full Schematics - Complete circuit details.

Micro-Amp:
A miniature amplifier and outboard power supply using the LM4780.

• Circuit design - details of the LM4780 implementation and the supporting electronics.
• Construction - point-to-point assembly, and lots of metalwork and woodwork.
• Power Supply construction - the power supply was a tight fit!
• Sound quality and conclusions - it's early days, but the LM4780 seems like a nice IC...
• Full schematic - high-resolution image suitable for printing onto A4.

Audax Mini-Monitors:
As a result of the recent Maplin stock clearance deals...

• Experiments - playing around!
• Enclosure design - details of the unusual enclosure.
• Crossover design - I even wound my own coils!
• Sound quality and conclusions - I was pretty surprised by these little speakers!

GainClones:
Monoblocks based on the National Semiconductor LM3875..

• Analogue stages - details of the LM3875 implementation.
• Control sections - 12V trigger input and front panel switch.
• Mechanical details - building them into the enclosures.

• Overview of the preamp and its facilities
• User interface: explains how the various options work, complete with screen-shots...
• Analogue stages - detailing the main audio signal path and the RIAA phono preamp
• Control hardware - the display, PIC PCB and front panel switches, etc.
• Power supply and mechanical details - all the small details...
• Full schematics - high-resolution images suitable for printing onto A4.
• Initial plans - starting as a simple stereo preamp, the need for multichannel, etc...
• Analogue research - as electronic volume control was required...
• Preamp FAQ - please check this if you have questions about the preamp.

Isolation Transformer:
An essential item for workshop safety...

Dual PSU:
Precision power supply...

• Introduction/Pictures: More on the initial specification, and pictures of the unit.
• Circuit details: Well, simplified block diagrams, at least...
• Testing: There's a surprising amount of parameters to test...
• To-do: There's still plenty to do...

• Main repair: Details of the initial fix.
• Other Faults: Everything else that went wrong.
• 'Scope 2: Thanks to this site, I've now got a second DM63.

ATC SCM20SL:
I've changed my speakers again! Check out the details of the latest arrivals here...

Rogers Loudspeakers:
Details of a range of products from this sadly missed manufacturer.

• LS3/5a's - The famous mini-monitors that are back in production again...
• LS5/8's - The flagship of BBC-designed monitors...
• Chord LS5/8's - The last LS5/8's used a Chord SPM800 instead of the retired Quad 405. ...
• LS5/9's - My favorite BBC speakers...
• LS7's - These were my main speakers for 5 years...
• dB101's - Don't be put off by the strange looks - these are great little 'speakers...
• Other models - Details of some other models made by Rogers over the years.
• Service/Spares - A problem since the demise of Rogers...
• Brochures - See some old Rogers brochures...

• Introduction - model history.
• Technical - Construction, circuit description, later models, faults and maintenance, mods.
• Related Musical Fidelity models - including the A100, B200, etc

Introduction:
What is a microcontroller?

• Introduction - what is a microcontroller, and how does it differ from a microprocessor?
• First steps - building a simple programmer, programming code into your first PIC.
• Configuring - step by step guide to configuring your PC.
• Architecture - a detailed look at the insides of the PIC.
• First programme - beginning to write code.
• Time delays - general purpose time delays.
• Subroutines - examining programme flow.
• Input - the beginnings of accepting external input.

Applications:
Using the PIC for a range of tasks...

• Coming soon!