I genuinely Need help.

I have a Node2i (tidal) and a Marantz setup and Im very happy , originaly I bought the node 2i a year ago and returned it cause didn't think it was worth it for the money over Heos. later on I seen it on sale New used Mint and for the money I bought it again and it was just as I remembered it- anyway I seen a New Cat8 cable from link up  22ga cable and since all my patch cables were 5E i decided to just swap them all out what the hell why not the cables are very nice just to look at  , I wasn't really going for a system Tweak I actually had no Idea it would raise the SQ like it did, Maybe something was wrong with the old cable cause it was like having a new component that got me thinking what other upgrades to the Source could I do? I want to try an upgrade for my SMPS (MU36-D120300-A1) for my Modem/Router/Gateway its a 12V 3A so Im looking for an upgrade on that and also while I was at it wanted to upgrade to the PD creative Board and PSU. I do not have a external DAC maybe one day but not now the node is serving me for now, can anyone recommend me a bullet proof linear 12v 3A power supply  and best mod for the node2I theres a couple out there  , I like my node I want to keep it for now Just make it better, I really believe garbage in garbage out so I want to do whatever I can to improve the signal going in. this is a hobby one of many for me so please if you have something negative to say dont bother responding to the if its not broke don't fix it guys.  I would get the IFI power wall Warts but the amps are wrong even the elite they offer dont line up on the specs. please advise