Australian Technical Production Services

Introduction

These are a few projects I have worked out over the years and taken the time to write up.
As I have designed Circuit boards for a number of these, I will be making 'short form kits available for sale.
Since Australia is not a country renowned for cheap electronic components, overseas visitors will more than likely be able to source the bulk of components more cheaply than I can, so the short form kits will include:
Assembly instructions, Printed Circuit board, Any preprogrammed devices such as embedded controllers etc and any more unusual parts (i.e. parts that are not readily available from companies such as Mouser or Digikey).

Project listing

Compact Foldback wedge 06/05/2013

With a sensitivity of 96dB 1W/1M at up to 200W this 32cm wide (just over 1 foot) wedge is small but still delivers plenty of level. Equipped with Tweeter protection for those moments of unexpected feedback....

Data Acquisition module/(Data Logger) 14/12/2008

5 channel 10 Bit Data acquisition module with input Signal processing board.
The Data Acquisition module uses a serial interface so it can be used with either an older computer or a newer one with a USB adaptor

DTMF Decoder/Display 14/12/2008

Displays DTMF signals on an LCD display

Dual crowbar 25/09/2013
Designed to protect a mixing console or other audio equipment against a power supply failure resulting in over voltage. This circuit monitors both a positive and negative rail triggering in the event that the power supply voltage exceeds a preset level.

EV SX100/300 Speaker cover (PDF Only) 28/11/2011
Even folk with my limited level of sewing skills can make up a set of covers for EV SX100 or SX300 speakers.

This is an instructional article only.

Medium desk Power supply 17/02/2014
This is the Bigger brother of the power supply above
+/- 13 to 18 Volts at 5 Amps and +48V at 1 A - more than enough power for many larger desks up to 48 channels.
Using Switch-mode Circuitry for efficiency and lower power dissipation it uses a readily available off the shelf Transformer rather than a more expensive custom wound one.

Microphone Pre-amplifier 09/04/2016
Based around the SSM2017 or INA217 this Pre-amplifier uses Servo Nulling and offers all the features you would expect from a decent Pre-amplifier such as Metering, High pass filter, 10dB pad and Invert switch.

Passive crossover with Active tweeter protection 04/08/2011
If you are interested in making your own speakers this Board offers all you need including Tweeter protection.

QSC K10 Speaker cover (PDF Only) 09/09/2011
As with the EV SX100 or SX300 covers, except for QSC K10 powered speakers.

This is an instructional article only.

Small (Microphone Pre-amplifier) Power supply 25/09/2015
At 109 x 23 mm this is the smallest power supply in this range, it is capable of delivering +/- 15 Volts at 1 Amp and +48V at 200mA - more than enough power for a Microphone pre-amplifier or two or as a replacement power supply for some smaller desks.
As it uses a voltage multiplier to produce the 48V rail rather than a separate 48V winding it only needs a readily available off the shelf Transformer rather than a more expensive custom wound one.

Small desk Power supply 09/01/2013 - Updated 18/02/2015
While the circuitry is nothing new, this is a handy power supply capable of delivering
+/- 15 to 18 Volts at 1.5 Amps and +48V at 500mA - more than enough power for many smaller desks up to 24 channels.
As it uses a voltage multiplier to produce the 48V rail rather than a separate 48V winding it only needs a readily available off the shelf Transformer rather than a more expensive custom wound one.