Want to talk of the external DACs.
As we do not have jack on our phone, here a little list of compatible DAC.
Ibasso DC01 ~50$
Unfortunatelly Ibasso says that there's some compatibility issues with Galaxy Series including Note.
It works very well on mine. N975F
Ibasso DC02 ("unbalanced version" of the DC01) ~50$
SMSL Idea ~85$
EarStudio ES100 ~99$
Audioquest DragonFly Cobalt ~299$
Hidizs Sonata HD-D ~30$
I've an Ibasso DC01 and it's wonderfull. I never had a sound like this with a smartphone.
Do you use one too ?