Resi recommends using one of the following audio embedders to embed audio on SDI for input to the encoders.
Blackmagic Design Mini Converter Audio to SDI 4K
Embed 4 channels of analog audio or 8 channels of AES/EBU digital audio into any SDI video signal over a 6G-SDI input. It provides four 1/4″ audio jack connectors for inputting and embedding your analog or digital audio channels. Learn more
AJA 3G-AMA
4-channel XLR Analog Audio Embedder/Disembedder. 1 SDI output. Compatible with 3G video signals and below (1080p60, 1080i59.94, etc). Re-clocked SDI Output. Learn more
Cobalt BBG-EM-AA
Embed up to 8 channels of Analog Audio into SDI via XLR with breakout cable BBG-CA-110-XLRF. Compatible with 3G video signals and below (1080p60, 1080i59.94, etc). Learn more