I got my 256GB from here
https://www.mouser.com/ProductDetail/Micron/MTSD256AKC7MS-1WT?qs=wnTfsH77Xs5bSygbrkOS9g==
Here's the industrial 512 GB
https://www.mouser.com/ProductDetail/Micron/MTSD512AKC7MS-1WT?qs=wnTfsH77Xs4I%2BMv7o3fRYA==
the price is worth it.
The above are what most have. they're i300 Versions.
The new i400 Micron Versions are out now but most sizes aren't in stock yet. only 64GB
This fortune 500 company also has some i400 Models in stock for $40 less vs mouser etc. They're based in Colorado, USA.
https://www.arrow.com/en/products/mtsd512anc8ms-1wt/micron-technology
Gonna buy a 64GB and see if there's any improvement in sound.
When you buy use the Chart below for write speed U1 vs U3 cards
read speed is the same for all cards which is what matters most for Music playback
https://www.mouser.com/datasheet/2/671/micro_sd_card_flyer-3043228.pdf
Micron has added a 1.5TB card i400 model (New release).
The new i400 models have an endurance of 5 years with 24/7 use vs 3 years 24/7 use with the older i300 models 99% of us have.
https://www.mouser.com/ProductDetail/Micron/MTSD064AMC8MS-1WT?qs=A6eO%2BMLsxmRix8Q5bXoMtQ==
They take a decent DAP like DX240 to end game levels of sound paired with the right IEM ofcourse that can pickup the differences.