The V10 is an older phone now. I think your questions best answered at XDA forums. RIP V10. Long live G6!
I still love my V10 by the way!
I don't find anything special about the G6 having a better DAC than what's in the V10? So not sure what is so better about it.
"Regarding audio quality, LG recently issued a press released which detailed the upgraded Quad DAC audio system confirmed to appear in the Korean version of the G6. This is said to be superior even to the Quad DAC included in the LG V20, which provides one of the best audio experiences of any Android phone ever. That said, it’s not clear whether this chip will be available in international versions as well."
Even if it has a so called better DAC chip wise, it's all still about implementation not just the DAC chip itself.