Upgrade Hint 6?

You'd be much better off selling your Hint and putting your $$$$ toward separates or a better integrated. That or just enjoy what you have.

DACs really don't get any better than what can currently be bought for ~$400. The technology peaked years ago and what's available now are basically two types: highly-accurate, near-perfect-measuring DACs (that can be had for a couple hundred), and DACs that color the sound in some subjectively pleasing way, with rolled-off highs, distortion, poor channel separation, etc. 

The Schiit Multibit DACs fall into the latter category - colored sound. 

OP, don’t be surprised to find disagreement among audio people.  Calling Schiit multibit DACs colored sound is not true.  And as one who’s owned three of them I think I know a thing or two about their sound.

Sorry, but I’ll also have to disagree with the $400 dac theory as well.  But one does need decent gear in order to hear improvements.  Good luck with your search.

"DACs really don't get any better than what can currently be bought for ~$400. "

I didn't know that. 

why are you assuming the DAC is the weak spot in the Hint ?