Warning: It would be irresponsible of me not to warn you that electrical and electronic equipment can be dangerous. There can be a risk of electric shock, fire, or other bad things if you do not know what you are doing. Therefore, information here is for use at your own risk, and by persons who have the necessary skills to use it safely.

Maintenance

Fixes, upgrades and hacks.

Soundcraft PSU 150 Rebuild

This PSU came with a Soundcraft 200 Delta mixing console (more about that later). It is basically a very good regulated power supply, but the years have taken their toll. A description of some of the issues that you might come across rebuilding a unit like this.

Dynacord Eminent Restoration

A classic old valve amp gets a full overhaul and a few choice mods to make it into a great recording tool.

KEF PSW2000/2010 Series Active Sub Woofers

These subwoofers are now discontinued, but plenty are still around. They run rather hot, and this causes failures. In this article I present some modifications which help alleviate the problem. Please note I no longer repair or modify these, as they seem to be quite problematic units. However I leave this page up, as it may be of interest or use to some.

Millennia HV-3D and Universal Audio 4110 Mic Preamps

I have been able to successfully repair these units. A brief rant about manufaturers of high end gear that make it difficult for people like me to fix their products, even when they no longer sell or support it themselves.

Hats off to ART!

A word of thanks to a company who I found to be outstandingly helpful in helping me get one of their older products repaired.

Numato Mimas 2 FPGA board

Brief review of my experience updating my digital design skills, using some great value hardware from Numato.

Reliability problems when MAX32 Dev Board is used with PICKIT3

Even with digits, it is an analogue world. The MAX32 dev board made my Digilient is a useful dev board for people working with PIC microcontrollers, but it gets unreliable when connected to Microchip’s PICKIT3 programmer. The fix turns out to be simple.

Embedded Software

Real Time Embedded Code On Small Microcontrollers (Part 1)

Real Time Embedded Code On Small Microcontrollers (Part 2)

Two articles that present a simple but powerful way to use Microchip PIC devices. The first shows how to reuse the ICP pins for serial debug statements. The second shows how to add a real time scheduler to the system.

Projects and Resources

8 ohm dummy load

This is a simple little project which is very useful for testing audio power amps and power supplies.

A Basic Audio Workbench

You don’t need expensive test gear that costs a fortune to do audio electronics work.

A 3V voltage reference

An inexpensive and easy to make voltage reference, which you can use to check the accuracy of your multimeter or scope.

An AD595 based equipment thermometer

A simply thermocouple based thermometer, useful for measuring temperature inside the case of amplifiers and other high power devices.

CD Handling Robot

A robotics project using a discarded inkjet printer to reduce the work in ripping my CD collection. And, it was fun to build!

Resources

Useful links and info.

Personal

Electronics Calculations Data Handbook

A book I wrote for Butterworth-Heinemann some years ago.

Royal Opera House

I designed and built several large audio systems for ROH in the late 1990’s.