400GB Micro card with iBasso DX90 and Cowon D2 succes without hassle, both work.

[parametrics]

maybe there are still cowon d2 users out there...
400GB Sandisk Micro card with iBasso DX90 and Cowon D2 (both rockboxed) succes without hassle, both work.
Had trouble with other card from Sandisk...thought i'd let you know which cards work.
Only a quick format with guiformat (FAT32) left settings as default.

This is the card:
https://www.dataio.nl/sandisk-400gb-micro-sd-ultra-geheugenkaart-uhs-i-a1-adapter/

Aanbieding! ( sale!) it's with adapter.
SanDisk 400GB micro SD ULTRA geheugenkaart
SanDisk 400GB micro SD ULTRA geheugenkaart UHS-I A1 met adapter

Opslagcapaciteit   400 GB (netto 360,0 GB)
Snelheidsklasse   Class 10, U1, A1, V10
Aansluiting (interface)   UHS-I
Leessnelheid (max.)   100 MB/s
Toepassing                   Smartphone, tablet, MacBook
Bijzonderheden   Inclusief SD adapter
Garantietermijn   5 jaar (Limited Lifetime)
Artikelnummer                   SDSQUAR-400G-GN6MA

number on the back of the micro sdxc says:  8473DVKX91TN
B0  MADE IN CHINA

Left to do for later:  modify the DX90, agreed ..it has a blacker background then the Cowon, but there's a hint of grainyness to the sound. If it would have the sound signature (more fluid sound) like the Cowon to my ears that would be a improvement. The bass is also a little dark and muddy. No matter how i tweak the sound i can not get rid of its grainyness.

Rockbox used on the DX90, ...(the mango dual boot with RB) 2016.07.16 (based on 2.5.1 + L3, by cholero@head-fi)
link: https://napych.com/other/rockbox-for-ibasso-dx90/official-rockbox-binary-builds/

Not shure if its the firmware that's not sounding quite right, cuz sound signature with RB is the same.
Cheers