I posted this small review on the SE846 & I think its relevant for this thread as well so here you go..
I have got the Ak100ii for almost 3 days pairing with SE846. I am aware of the impedance of 2 ohm of the headphone out but decided to give a shot as chances that 2 ohm may not swing that much although less than 1 ohm would be ideal. After some intense shoot out will all my 1ohm portable amplifier including the Hugo, I notice that the impedance "mismatch" has become its strength rather than weakness.
As expected, the bass went up, but luckily its not the mid bass bloat, but the sub bass shot up like 1-2 db more than all my 1 ohm portable amps and is now at similar to Hugo bass level.. Very very good. Deep and impactful with great control, never muddy or bloated. It just so well control here. Now what surprises me is that the level of perceptible treble did not decrease like ZX1, in fact, it has some extended boost to it so much that its a hair more treble at the very top than Hugo, I was thrill, despite the impedance of 2 ohm into 9 ohm SE846, the clarity is superb. In fact the treble level is on par with a 1ohm portable amp like Pico silm. Overall the AK100ii sound neutral with slightly boost in the sub bass and not mid bass thereby making less prone to bloat & an overall warmth with SE846.
I do find the vocal a little distant and that is expected from AK tonality, there is a little lacking in body but nothing serious, that being said, for those who find the SE846 shouty or too mid centric will appreciate this quality as they both pair up so well that I don't really find it lacking overall in comparison to say TH900 & Pico slim. There is still more vocal on SE846/AK100ii than those 2 combo.
It has a balance (1ohm) and Headphone out (2ohm) impedance. Power button at the top like Iphone.
Man - I love the dedicated volume control. This vol control is so refine, I think it is design for sensitive IEM like SE846, I can get any level of volume with this, I believe there are 75 steps overall. Unlike Pico slim or Dacport, a little turn is sometimes too much. Its clickable and each click is 0.5 steps. Volume can also be control on touch screen by sliding up and down anywhere after one click on the wheel.
Love the size, its pretty small and really easy for pocket .
But then, its not slim, its as thick as a cig box and weigh 6.6oz with leather case
Despite its small footprint, this toy has an impressive 192Gb storage overall. 64gb internal and 128gb Micro SD card.
Now compared to my dedicated portable amp, I would not say the AK100ii beat them flat as a dedicated portable amp like the HiFI M8 has way more power and can easily drive most of the planar magnetic phones, the AK100ii has almost reach its peak when driving a HD650, but then the HD650 is not that easy to drive to begin with.
I am still burning in and sound may change over time so this is just an initial testing phase. I have now understand why so many audiophile love the Ak tonality, the AK100ii has a lot of resolution and details, and tonality is pretty neutral, so that leaves one to choose the kind of tonality they like on a headphone which is good. The sound stage is on par with amps like Pico slim but I wish it was as good as Hugo (asking too much?). If there is a con, I would actually love the SQ to have more body and rich like the Hugo. There are quite a number of experts mentioning that the AK 240 tonality is thin and flat, I cannot disagree with this statement as it could be thin and flat if pair with another flat neutral phone, but since this is SE846 thread, all of us will not have this problem..
AK 100ii provide some useful EQ - from 30, 60, 120, 250, 500, 1K, 2K, 4K, 8K and 16K. These are exactly what I wanted for EQ especially on the bass level 30, 60 and 120, and this pretty much covered what I need for just the bass.
In short, I love the AK100ii, it's s probably has the most function in a DAP out there for its price at $899. Functions I really love like;
1) a very very good Amoled screen with great UI, with no lag at all, just turn it on an we have a selection of Songs, Albums, Artist, Genres, playlist and folder, no need to scroll wheel or so several click to get to this... any better, it will be the Iphone.
2) Use as a dedicated DAC and Amp for my Macbook and PC
3) Have a balance out and best of all its 1ohm impedance (need TED help to terminate me another cable)
5) Nice aluminum body and a real (not fake) leather case that is really beautiful
6) It can stream lossless files from PC using WIFI to AK100ii
7) Easy Drag and drop files for transfer or use Jriver
8) Useful & good selection of EQ
9) love the dedicated volume knob (dun like button vol found most phone today, the knob has very fine level of adjustment and because I am too old school - I just love knobs)
10) Side control play, skip and back (I just reach my hand into pocket and easily adjust vol and skip track without looking)
11) Digital output to connect to my home rig - S-PDIF output via heaphone jack
12) 24bit/192kHz digital audio playback (converts to PCM).
Ok for $899, I got features I really like.. I am impress with the SQ as a DAP with SE846 that I am now curious about the AK120ii ($1699).