[CallasFan]

Hello, i've recently purchased the Xduoo XD-05 and am wondering what the best way to connect it to my Fiio X3 is. I'm using the Fiio's line out to the XD-05's AUX in, which is fine, but will i get better sound quality by using the Fiio's coaxial out to the XD-05's  digital input? If this is the case, where can i get an appropriate coaxial cable? Most that i've found online don't have the correct connectors. It looks like it needs to be 3.5mm connectors on each end.
Any help is greatly appreciated!