Could you do a test with the attached presets and let me know your results.
You will need to load a clean project with no other tracks or effects active.
Open Activity monitor from Applications/Uilities.
Set activity monitor update frequency to very often (1 sec) (its 3rd item down in view menu)
double click on the Studio One process.
for each preset let me know what your idle is (when no notes are pressed ) and the % when 1 note is pressed.
CPU Test No Mod.SndPr (20.8 KB)
CPU Test With Mod.SndPr (20.9 KB)