RCA outputs to COAX input - is there only a splitter or is a extra device needed

Thnx but I have to wonder how the quality of that signal will be ?

Thank you both for your help here. So I am learning and see that I do have some choices to make and comparison shopping to do. Purchasing a  new DAC that has streaming capabilities would mean selling the Vault which frankly doesn’t phase me except going through the pain of listing selling shipping etc. or as you suggest Dj getting an analog to digital converter and getting one of  the DACs I mentioned in my post ( would this be cost effective compared to going for the high end glass Toslink  which eliminates the need for the ad converter? I’ll be reading up on the links you provided. Thanks again.