@rotijon
do you need an all in one solution?
if you like the geek 450 get the plastic pono. I owned both for 2 weeks and A/Bing with my UERMs and with/out my piccolo amp, the geek had slightly better separation and timber but I could only tell when they were right next to each other. Get the plastic I had the metal and it felt cheap as hell. things to worry about:
ui is slightly better(if not as bad as) the first gen ak100+ak120
battery life is like 7 hours with 16bit flac
I don't recommend anything with digital volume as every manufacture tries to find a middle ground between full size cans and iems so unless you listen really loud volumes you will be at the lower end of the volume and the dynamics and soundstage will suck (yes I am aware that both the geek and pono have digital volume control but I was attempting to work at your reference point). but if you insist on a modern dap here my opinions
ak240-does nothing wrong pretty neutral and dynamic for a dap (and guess what the new ak100 &120 II sound almost exactly the same<single ended>)
old ak100 &120 - yeah even without the mods sound slightly better?
they have more bottom end but overall not to far from the newer models
calyx M- its so warmmmmmm if I ever had frostbite in my inner ear I wouldn't reach for a hot pack I would put on some headphones and listen to the calyx. If you like the warmth of the original lcds this is for you (thought it packs a lot of power so be carefull cus I don't think you'll have that much control of the loudness with iems. I listen to the roxxanes and I prefer the 16s but they both have this well articulated bass that the calyx would ruin.
if you got cash and are to cool for school (don't care what others think) get a hifiman 901s a little to clean for me but with analog volume control and an amp specific for IEMs this is your best all in one solution. Great sound stage and separation I could have used some more juice on the lower end but the roxxanes might not need it. (the 901s is suppose to be the new model that keeps the sonics but fixes a lot of the dap specific issues.
if you don't mind a stack ....
TBC ..... my piccolo amp (never heard the leckertron and only have heard a head-fier give me a indirect comparison with the piccolo: leckerton vs vorzuge pure 2 Winner: vorzuge pure 2 <but warmer than leckerton> (other comparison) vorzuge pure 2 vs piccolo Winner: tie <but piccolo not that warm and when on sale $560 vs $330>) works pretty good with my ipod video so I am going to try to take LFFs advice and DYImod the thing to get better sound.
*obvious only thinking about sound here other things come into play. I like a neutral sound sig as clear and dynamic as possible. YMMV
