Your converter doesn't support dolby, or any mutli-channel audio. Try this one: https://www.amazon.com/Wiistar-Optical-Decoder-Support-Earphone/dp/B012EY84NE/ref=sr_1_4?ie=UTF8&qid=1528242255&sr=8-4&keywords=7.1+digital+to+stereo+analog&dpID=41l7RkDXLOL&preST=_SY300_QL70_&dpSrc=srch