thanks Threni.
I'm not sure how much the d10s can be modded without putting the board into a bigger box.
To me, the easiest and worthwhile mods would be:
-Changing the 5V USB supply with something like sigma11 or Salas shunt regulator. There are also smaller IC regs like lt3045, tps7a, adm7150,etc or even lm317. First thing i would do and not UBER complicated, if you have «desire», and possibly great rewards.
-Replacing the SMPS thats feeds all the clocks to a respectable linear or shunt reg, at least.
-Replacing the 3 big ALU 470 uF caps (with nichicon KZ (They have leads though) i would personnally) (to be tried at the minimum but you may not like the results)
-replacing buffer/filter op-amp with a better op-amp or discrete circuit, to taste.
Bonus 1: you COULD want to change the +- 5.6V SMPS that feeds all the dac output stage opamps.... these opamps have good Supply rejection though so it would be interesting to try.
Bonus 2: Ditch the 3.3v tiny reg dac feeds the dac chip with something better (though i'm not sure what is this reg exactly).
Disclaimer: you may damage your unit or not like the results, which also depends on how well it is implemented.