When using HE-XDAC007 & HE-XDAC107 with an HE-XE104, HE-XE105, or similar XL models with a 13 pin bottom I/O connector, the add-on module connector interferes with the stock I/O board connector. It is necessary to order a replacement I/O connector available as part number HEXKIT45. This is not necessary for the 102 and 103 style XL units.