aune s16 is one of the best dac I have heard next to chord hugo, dcs, best 9018 implementations, old multibit dacs - have in mind this is delta sigma 'crap' based dac !! but from epic japan asahi kasei, only one that can play music (even old ak4396 in some nice implementations could play music like it should, newest ak4495 is a delta sigma revelation for me, having all the detail, realism, transient response, speed, amazing bass, texture, deep and wide soundstage +there is that amazing spark in the highs like in real world)
but the amp is something fuc*ed up there or maybe I demand too much from combo in this price range, yes there is some background noise even on he-4 which is 86db sensitivity which is freaking ridiculous and it needs some correction immediately, not even mention some high sensitivity cans, this is unacceptable to put something like this into a combo with such wonderful dac, aune x1s amplifier section is MUCH better in every aspect and it costs 1/3 of s16 price but the dac implementation there even though it's 9018k2m can't compare
btw display is so cheap, the backlight is so bad (leaking on every side of the display and in the corners), they should have used OLED - that would be epic and it's not so expensive these days, come on aune...
but the dac itself has amazing potential, the power supply section is perfect, epic usb interface with FIFO reclock, clocks are perfect, adum isolation, pcb is like 1 million dollar project, pga volume regulation, epic analog output stage and best delta sigma on the market - everything is done there like in the best equipment I have seen
if they make amp sing like it should I will buy one unit immedaitely, and it's not only in noise (it's not like the typical noise / humming, it's like some static distortion, there is something going on there that is wrong and it was in a few units I have tested and with every headphone I tested, hope it's not oscillating or something) it's also something strange in sound that extremely exhausts my hearing after short time of listening when I turn the volume up for like 80-90 to get proper SPL with my hard to drive HE-4, guess it must be awful kind of distortion, I have never had this issue before with many other amps from audio-gd, schiit lyr/asgard, hifiman ef-5/ef-6, beta22, wooaudio, rudistor, even speaker amps driving it like emotiva
but once you match the dac section with some resolving, fast and detailed amp that is neutral in its sound signature something wonderful is happening ... and every single music track is another adventure, so much to discover, don't use internal headamp, pair it with good amp and you will be amazed