Hope it's not too late to reply. Using DAP to stack with DAC amp, DAP only act as a source in providing digital files. However, the quality of digital out does affect the sound quality and sound signature as well. So different players pairing with Mojo will actually give you different sound.

This is also the reason that you can find very expensive media players that people use in their HiFi system, mainly providing digital source only.

So far from my findings, players digital out is definitely better than hand phone (micro usb otg / iphone lightning)
In terms of player digital out quality, I would rank it this way. (best rank first)
1) Cayin N6 (provide most details and good separation. Sound is solid and could be aggressive to some) -coaxial
2) Sony ZX2 (It's comparable with N6, with softer and smoother sound, more musical and very easy to control)- WM port -micro usb
3)iBasso DX80, DX90, DX50 (iBasso player actually has very good digital out quality, except DX80 is a little bit warm sound. For those who likes cleaner sound may prefer X7 over DX80) -coaxial
4) Fiio X7 (Quite clean and it's android base and support music streaming. UI is not as fluent as ZX2 as a source)
5) Fiio X5, Cayin N5 - coaxial
6) Fiio X3II - coaxial

Haven't really tested out AK players hand to hand with the above players so no comment. Usually coaxial sound quality would be better than optical base on our experience (referring to the same device with both optical and coaxial) and it's easier for you to find a better quality coaxial cable.

Hope this helps. 

Thanks for the VERY details reply. It's help a lot.

Haven't really tested out AK players hand to hand with the above players so no comment. Usually coaxial sound quality would be better than optical base on our experience (referring to the same device with both optical and coaxial) and it's easier for you to find a better quality coaxial cable.

Hope this helps. 

Anyway DAP feel like very bulky, if you bring out on both hand with DAP and Smart phone, btw you might do more with smart phone as well.

Recently I had tested with AK 100II the sound slightly better than iPhone 6s only, but when iPhone 6s plug in with mojo the sound totally was different a lot.

Maybe you can try it out, cause my currently setup with iPhone 6s or Mi Note with Mojo and RHA T20I the sound really impressive very different signatures. 

If wanna budget still can consider for Fiio DAC much cheaper to compare with chord mojo

Too bad, AK players only support optical cable output.
BTW, Happy Chinese New Year

Anyway DAP feel like very bulky, if you bring out on both hand with DAP and Smart phone, btw you might do more with smart phone as well.

Recently I had tested with AK 100II the sound slightly better than iPhone 6s only, but when iPhone 6s plug in with mojo the sound totally was different a lot.

Maybe you can try it out, cause my currently setup with iPhone 6s or Mi Note with Mojo and RHA T20I the sound really impressive very different signatures. 

If wanna budget still can consider for Fiio DAC much cheaper to compare with chord mojo

I always bring both: my AK100II on my hand, my Note 5 in my pocket, since my hand palm is big, I can use my Note 5 with 1 hand.

Sound quality wise, it is always a debate between smartphone and DAP, like my case, AK100II vs Note 5, definitely AK100II wins but not edges Note 5 too much, only in tiny details and dynamics.

If choosing smartphone as music player, users should opt for large storage capacity or with support of microSD, inaudible noise when paired with low impedance IEM, better stereo crosstalk (you can check in review of the smartphone). dynamic range etc

Agree with you.. Maybe I was still not finding the right dap to fit with me now.

Copper AK380 with Copper docking amp, that is it lah

Not my taste wow, after look at the leather case, feel like I am too older already, maybe will be my choice of Cowon Plenue S feels more sexy to me

Well if there is your choice, please buy the Cowon dock for Plenue S too

my next upgrade is slightly of different than others ---> Sony PCM-D100

No lah, my next will be on the little bro, cowon plenue D

I won't invest too much on dap as well, I would rather than buy more IEMs

No lah, my next will be on the little bro, cowon plenue D

I won't invest too much on dap as well, I would rather than buy more IEMs

It is not even upgrade compared to AK100II, may on par of

I stop invest in IEM after I get my SE846

Is Cowon plenue D good? how much is it?

I guess low end or jk junior level does not come with optical input

I always bring both: my AK100II on my hand, my Note 5 in my pocket, since my hand palm is big, I can use my Note 5 with 1 hand.

Sound quality wise, it is always a debate between smartphone and DAP, like my case, AK100II vs Note 5, definitely AK100II wins but not edges Note 5 too much, only in tiny details and dynamics.

If choosing smartphone as music player, users should opt for large storage capacity or with support of microSD, inaudible noise when paired with low impedance IEM, better stereo crosstalk (you can check in review of the smartphone). dynamic range etc

Well if there is your choice, please buy the Cowon dock for Plenue S too

my next upgrade is slightly of different than others ---> Sony PCM-D100

Using handphone as digital source, I would say iPhone is rather safe even though you have to spend a little bit more money on the camera kit / lightning cable. But in return, not so many compatibility issues like android, also the digital out quality is better than lots of android devices. My previous MI3 with Mojo is a disaster to me. It sounds better when I switch to Note 5 and iPhone.
But again, pairing Mojo with DAP such as N6 and ZX2 give me even greater surprise.

Sony D100 is a good choice. Strong amp and good details just that a bit bulky. Hai Wei used to owned a D50 for recording live performance.

Best mp3 below rm700?