EXTC-SA™ Using & Applications

The Radial EXTC-SA is a professional audio interface that takes a balanced line level signal and converts it to an unbalanced guitar-level effects loop and then re-converts it back to a balanced line level for processing. It is designed to be used with both traditional API style 500 series Lunchbox™ frames and the more advanced Radial Workhorse™. This quick reference guide assumes you are familiar with 500 series modules and racks.

Complete details on using the EXTC-SA and making connections to and from your 500 series rack can be found in the manual (PDF download).

Making Connections
As with all audio equipment, always turn levels down and/or turn equipment off before making connections. This will help avoid turn-on transients that could damage speakers or more sensitive audio equipment. Plug the EXTC-SA into the Workhorse or 500 series rack. There is no power switch on the EXTC-SA. It will automatically turn on as soon as it is plugged in.

500 racks are usually equipped with a balanced XLR-female input to connect from your recorder and a balanced XLR-male output to send back to the recording system. If you have hi-z send & returns, you can use XLR to ¼" adaptor cables. If you have a Workhorse, the rear panel ¼" jacks can be used.

To connect your pedals, simply plug the ¼" send to your pedal chain and the output of the pedal chain back to the EXTC-SA receive input using standard Hi-Z guitar cables. We suggest you start with one pedal first before using acomplete chain as this will make it easier to trouble shoot when first setting up the EXTC-SA in your system.

Checking the Signal Path
Begin by setting the send and receive controls to 12 o'clock and the blend control all the way clockwise to the 5 o'clock wet position. Turn on the effects and play the desired track. You should be able to monitor the return path in your recording system and hear the effect. Separate send & receive controls makes it easy to adjust the levels to suit. Now, try varying the blend control by rotating it counter-clockwise towards the dry setting to hear how the effect mixes in with the original track. If you notice that the signal is 'thinning out' when you are adjusting the mix, the wet and dry signals may be out of phase with each other, thus causing cancellation. Try depressing the 180º polarity reverse to fix the problem.