PSU power supply mods modifications questions

[paulrichards7]

For my ever on-going electronics self education
I was wondering what kind of modifications can be done to power supplies of various audio gear
From my understanding(which is still rather limited)stopping noise from getting into the audio path is of major importance, which makes sense
Increasing capacitor size helps the low end(bass), have no idea how it does this
Seeing as pretty much every piece of studio equipment has power supplies, wouldnt this be the first place to mod?
Having said that, where does one start?
Obviously you would need the relevant equipment(oscilloscope, wave generator, multimeter etc)
Thanks
Paul