If I make one observation - a comment, not a criticism - there is a definite bass boost in there. This becomes obvious amping the signal with the Heaven VI. The bass is gaining up more than normal. I like this. It encourages listening at lower volumes where the extra bass falls into place nicely along the Fletcher-Munson curve producing a great sound.
(As a standalone DAP, the bass also compensates for the amp being a bit on the thin side. I still do not plan to use the DX50 this way.)