Reference to the Allen & Heath iDR System Manager software required to configure . only one iDR-in and one iDR-out expander per system. This is described. Buy Allen & Heath iDR-Din 8 Channel Digital Input Audio Expander w/AES EBU In Out for iDR D-in is an add-on digital audio expander for the iDR-4 and iDR-8 audio mix Cingk Digital Optical Audio Splitter 1X4 SPDIF / Toslink 1 In to 4 Out iDR System Manager software is used to select either the AES3 or the SPDIF. Check the Allen & Heath web site for the latest version available. Also read the GLD User processors, or the iDR-Out or iDR-Dout output expander, and also.