I use this one and it works great, silent noise floor located up against the shielded side of the power supply (away from the video card).
https://www.amazon.com/gp/product/B071P5C6CS/
Thanks for the link
It probably is best to test an standard usb pcie card first again, i did some tests a while back as i was still using windows and they definitely made a difference, but not one where i would say one usb port/card sounds definitely better than the other, but still they sounded different
i just recently switched from a rpi4 setup back to straight usb from pc (because its just more convenient on a PC setup...)
i found this card:
https://de.aliexpress.com/item/1005005913316841.html
it does not feature a VLI or ASM usb chip but one by Renesas, which might be a interesting comparison too, since i think i never had a renesas usb hub, the usb hub chip itself probably determines noise to great degree
There was also some talk i read on audiophilestyle about the different chips, and some expensive audiophile pcie cards actually seem to use either AsMedia or Renesas
The VLI805 on the raspberry pi 4 didnt sound that bad either tho
In theory it also isnt that hard to add a external power supply slot and an external clock, but i have to see how much of a difference the pcie card still makes after the ifi isilencer and my diy filter
Also I undervolted my video card for more performance but also less interference and it helped a lot. The best article I've seen was Archimago who did extensive testing.
https://archimago.blogspot.com/2015/05/measurements-corning-usb-3-optical.html
yea this can definitely made a difference depending on your setup, i still remember in the beginning of my career i was able to hear my mouse moving trough the speakers with a straight usb wire, not sure how objectivists can argue that usb is perfect but thats another topic
i also felt like going from RX560 to GTX1070 made an improvement a few years back
Tho i think currently im at a point where the PC doesnt sound "obviously" worse than a raspberry setup, which is kinda great and i thought impossible for a while
One of the last upgrades was to go for a higher quality mainboard + Intel 12400 (and keeping my GTX1070, i dont play much games these days...) and actually putting everything into a LianLi aluminium case