Loaner DX100 v1.1.0
Tested w/ 16/44 and 24/96 wav.
Phones: UE IERM

 
User experience:
Noise from manipulating the screen and track selection.  Sounds like my tracks are being electrocuted or a moth is flying into a zapper each time I select a new track.  Other random noises.  The screen is annoying, keeps rotating and has delay finding right orientation. Cuts off the first half second of the track when skipping to another one.

 
HO
Serious solid state glare and bite to treble and sibilance.  Where's the resolution?  Sounds grainy throughout.  Decently wide and spacious.  Good separation, not resolving, wavs sound like mp3s.  Present bass but some percussion/drums sounds plastic.  Rough, dry and crispy signature. Timbre isn't right in the low end,  cymbals are tizzy, a lot of the spectrum off.  Hmm, is Harry Nilsson playing a guitar or a harp?  Los Lobos sounds like they use Ukuleles rather than guitars too. This is going to be fatiguing, have to switch to LO asap.

 
LO > UHA6S (OPA209)
Grain and glare mostly gone, still a bit of spitty sibilance in the vocals, must be the DAC.  Right away more micro detail exposing the track (background noise, clicks and pops from analog tape masters for example), more air and layers.  No fake detail from boosting treble or thinning a signature.  Cymbals and treble still seems a bit mechanical but less tizzy.  Bass timbre is more correct, percussion sounds right, drums are organic and natural.  Ah, Chet Baker is fixed, not hollow or nasal anymore. Trumpet, Sax, Piano, double bass all sound largely correct for the most part.  Harry Nilsson's vocals sound richer and natural w/ more detail.  His guitar is back along w/ Los Lobos.  Note weight to strings restored, reverb in the instrument's body, proper string plucking is evident and sounds real.  Smooth resolution.  Notes trail away and decay naturally and fully extend instead of being rough, curt samples.  The first 10 seconds of Kool and Gang's Ladies Night gives it all way between the stock amp and the Leckerton.  Natural, accurate percussion, proper cymbal timbre on the high hat and crash w/ even natural ringing and trailing decay; clear, clean vocals, horns and clap machine.  Done.

 
I think the 801 is a more resolving DAC despite it's darker signature.  801 original stock amp is still one of the worst I’ve ever heard even compared to the dx100 but it's still bad IMO.

 
Just went back to my Nokia > UHA6S to A/B.  I'm done w/ the iBasso DX100.  I won't be listening to it anymore until some magical firmware fixes everything.  Unfortunately, after going back to my normal setup the iBasso's hi-rez DAP sounds more like an mp3 factory.

 
+   built extremely well, very pretty.
_   sounds best feeding optical to my UHA6S