We've added a special new section to the DSDT Database called Optional 7-Series DSDTs. Since Gigabyte 7-Series motherboards don't normally require a DSDT at all, these DSDTs were made with minimal edits to enable Intel HD 4000 audio output. The first two we've added are for the CustoMac Mini 2012 motherboards: the Gigabyte's GA-H77N-WIFI and GA-Z77N-WIFI. We'll be adding more of these soon. Enjoy!
Inside MultiBeast: Audio and HDMI Audio
Building a CustoMac: CustoMac Mini 2012
Official CustoMac Mini 2012 Guide and Notes (in progress)