Digital tweaks or upgrades that do work

Having lots of computer based audio for over 6 years or more from the 1st Bryston digital player 
which was not always smooth saying with firmware issues, 
currently I have what I feel the best Dac -Streamer high end value in Audio ,the Bricasti M3 with Streamer board Roon ready. Tweaks, upgrades that truly work , taken from their upper end dacs 
Sill points I put the ultra mini  under the dac , and also have a polished slab of granite which makes a outstanding anti vibration piece and a 15x15 piece polished$150:a true bargain , the Still points just add to the musicality ,stereo separation and detail, not cheap $500 retail  but work well.
the Ethernet hub or switch ,the stock netgear is noisy ,a noticeable improvement is the Uptone Audio
Ether Regen which cleans and isolates the signal going to your streamer, 
the Ethernet cables also a very noticeable increase in resolution , I am using the very cost effective 
Wireworld Starlight from modem  to router , and I currently have a long 32 ft run of Beldons top  cat 6 certified 500 MHz , which I will be upgrading with the same Starlight 10 m , the most difference noticed though is from the Uptone Audio  hub to the streamer which I am also using  the Wireworld starlight  cable at $210 a M
a true bargain  cat8; Ethernet cable. Lines are dedicated awg10 -4 wire dual ground , 1 common ground 
1 insulated isolated ground ,  with 2 -5Ft Copper grounding rods.