Don’t use the Toslink connection — you’re better off using SPDIF. Upgrading your digital cable can do wonders depending on what you’re using now. I was using a decent budget cable, but when I upgraded to this AZ MC2 cable (there are reviews online you can read) the sound improved dramatically — and I mean dramatically— in every way so that might be an avenue to explore, and your excellent DAC will certainly appreciate it. Here’s one for sale just fyi…
https://www.usaudiomart.com/details/649951192-acoustic-zen-mc2-digital-coax-cable-1m/
Best of luck.