hi, I would like to note that the "noisy" behavior of the device might have to do with 2-3 aspects mostly,
1. low quality psu: light as a feather, probably noisy. I suggest to retest with a better quality one. Also a li-ion battery powerbank supply @ 12v could produce better signals, I use one of those. The unit do not consume more than 0,5-0,6A probably less as a DAC.
2. A noisy usb port, there has to be a test on battery only or with a mobile phone @ OTG USB mode to be sure.
3. The DAC's usb controller, probably adaptive mode, model via vt1630a, an audio codec ADC/DAC chipset with DSP but only the controller is being used here, there might be a bit higher jitter there but this needs special equipment to measure,
this can be audible probably only on higher end systems or headphones.
So, there might be cheap solutions to reduce noise and reclaim better behavior in those tests especially on the last one.., just a guess.
note1: newer models seem to use an other alternative solution for the USB controller: Saviaudio SA9023 chip.
note2: ASIO drivers do exist (probably a kernel streaming wrapper, works ok with foobar2000):
https://www.head-fi.org/threads/fx-...tial-sub-100-king.809203/page-4#post_13063331