Well, i asked if there were any options to the Leckerton UHA-6S MKII in the price range, and someone recommended me that Muse DAC which costs only $20, so i guessed the SQ difference wasn't worth the money gap?
Actually i was willing to spend even more on a Yulong D100, but i don't know if it's worth the money either. That's why i came here to ask.
If you're interested in the Yulong D100, you might want to look at the audinst hud-mx1. It's about 170 USD, but I find that the dac section sounds amazing(very, very natural).
And the built in amp really drives the HE-400 well, much better than my fiio e9 actually (again much more natural sounding).