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The following is the basic approach one would take to use the SW8 in a stage setup. Please consult the complete user manual for full details on using the SW8 as this will provide important safety tips and helpful suggestions to ensure the SW8 performs properly. As always, make sure your audio system is turned off before making connections.

Connecting the SW8
The SW8 is equipped with standard 25 pin D-sub connectors plus ¼” TRS for 8 channel balanced input connections. Start by connecting your playback systems to the two inputs. If you plan to use an unbalanced ¼” source, connecting a mono ¼” plug into the TRS inputs will automatically unbalance the inputs. Your main machine would be connected to input-A and the backup machine to input-B.

The SW8 has two sets of outputs: The rear panel D-subs would typically be used if you are connecting to a line level device. The front panel XLR outs are actually Radial transformer isolated direct box outputs. These would be used if you intend to send the output of the SW8 to a snake system and mic splitter to feed the mic preamp inputs of your console. For added convenience, you can go inside the SW8 and connect the transformer outputs to the D-sub output by simply moving a jumper cable.

The SW8 automatically turns on as soon as you connect the 15VDC power supply. Once connected, the one of the front-panel switrch LED's will illuminate. We suggest using the cable lock once your system has been tested to reduce the risk of the power adaptor disconnecting in error.

Start by testing the playback connections by playing a signal through input-A. If all is OK, then depress the front panel A-B switch and this will turn the input-A set off and turn on input-B set. If you plan to use the transformer isolation output option, a global -20dB pad is available. This would typically be used if your source is a line level device. During playback, if you notice distortion, you are likely overloading the transformers. Simply depress the pad switch on the rear panel and this should address the problem. You can alternatively reduce the output from your playback machines.

Switching options
In addition to using the front panel A-B switch, you can use any type of contact closure to remotely switch the SW8 such as a standard latching footswitch. Above the contact closure input is a remote output. This can be used to send a contact closure to another device.

To use the auto-switch mode, you must turn it on by depressing the recessed ON switch on the rear panel. Once on, the SW8 will now switch automatically as soon as the signal level going into the auto-switch circuit drops below a pre-determined level. This level is adjusted using the threshold control on the rear panel. It is recessed and made hard to get to so that one set, it is out of harms way!

Any steady tone will work. This can be a tone inside or outside the typical audio bandwidth and can even be a steady state digital tone such as one generated by a SMPTE clock generator. A dedicated auto-switch input jack has been provided to allow you to use an external device to generate the test tone, thus leaving all 8 channels for switching audio. Input-1 on the D-Sub can also be used for the steady tone if you prefer.

Test the switching function by reducing the level going into the SW8 auto-switch circuit and then adjusting the threshold level to suit. This is basically a signal gate that has been augmented with a 3 position band-pass filter. The filter control is accessed through the top panel using a tweaker to move the slider switch. All the way to the front turns the filter off. A mild filter is in the middle position while a more severe filter can be turned on by moving the switch towards the back.

The Link Function
To expand switching for larger multitrack systems, a simple link function has been provided. Simply determine which SW8 will act as master and connect the master out from it to the link input on the second SW8 using standard 1/4'” guitar cables. Once the links have been connected, the slaves will automatically follow the status of the master SW8. Should power ever fail, the SW8 will revert to the input-A set.