Speaker Workshop Jig

Those of you who use Audua's Speaker Workshop software would no doubt be aware of Eric Wallin's jig to connect the testing hardware to the PC sound card. While this jig certainly works and is much better than different cables and alligator clips, the switch combinations are not real intuative and it is another external box with cables. As I was building up a PC especially for audio measurements (old AMD K6-500 desktop), I decided the jig should be inbuilt. I had a few interlocked push-button switch banks around, so I thought this would be a good opportunity to set up easier switching. By coincidence, I happened to have the same sound card as Eric, so did his modifications as well.

The desktop case I was using had two spare 5.25" drive bays, so I made a bracket to utilise this area. The switching was set up in calibrate and measure groups which makes it easy to select the correct function. The pad switches are separate, mounted next to the inputs they operate on. To keep things compatible with other equipment, all inputs and outputs are 1/4" jack sockets, with the input sockets using normalising contacts to provide an alternate connection when the socket is not in use. As this PC was also going to be used with other software such as Smaart Live and TrueRTA, I provided inputs and outputs on all channels. The PC case also has a heap of room behind the drive bays, extending all the way to the back of the case underneath the power supply, and I intend to make and install a power amp and associated power supply in this area for high level testing - hence the volume control and XLR speaker socket on the jig panel.

Front and rear views of my jig are below.