>this new one sounds much better than my previous version

I have aboslutely no idea lol, I love mine. For me the Xduoo doesn't do much different in comparison to my FiiO K5 pro ESS, maybe due to the ESS chip, who knows. I will most likely sell my Xduoo soon to get a Eufonika H5, that is if I can even get rid of it. Swapped to potentiometer and now I have a black knob TA-26 (I bet there are people who want exactly that though, maybe I am lucky).

It's a great amp for sure, but I want more tube sound.