It's an impeccable source unit (i.e. transport) to use with an amplifier like the JH-3a. I use mine with the Tralucent T1 amp which of course negates any of the output impedance issues (as will any amplifier).
Tm.chen's suggestion of listening to one first is always good, but you've already ordered it as I understand and depending on where you are, that can be difficult sometimes. The good news is, I don't think I've heard anyone complain about the sound from the AK100 (assuming the output impedance isn't an issue which it won't be via the JH-3a)
Guys, there are far better choices for the JH-3a than the AK100. The AK only has optical out & the 3a needs either usb or preferably coax to really perform well. Feeding the 3a an analogue signal just adds multiple unnecessary conversions. The 3a does all it's processing in the digital realm so feeding it analogue means the conversions are Digital to analogue (in the AK) then (in the 3a) analogue to digital, DSP, then digital to analogue again.
It needs a digital signal so regardless of how good your analogue source, your better of with a digital one.
So a better choice would be something like the new fiio x3 with coax out. Much cheaper too. Also DX100 & colorfly have coax out. I have tested my 3a with very high end desktop dacs analogue signal and even usb beats it noticeably. Then a good coax, noticeably again.