Thanks in advance for the input. I have a Samsung UN50NU6900FXZA that is being under-utilized with my FireTV. I've tried using audio extractors in combination with a FireTV Cube, but there were always issues. I want to purchase an Nvidia Shield Pro and pair it with a decent headphone amp/DAC that I can use to send audio to my old Pioneer VSX-D902S receiver via Line out or RCA. I've looked at the Monoprice Liquid Spark DAC and the Fiio K3 V2 that were around $100-110. Would either one of these be adequate? Any better suggestions in the same price range?
Absolutely dont do any of that.
Your best option would be to go for a simple soundbar with HDMI-IN.