I did some OPA rolling with SU1, but I'm definitely know that this below is my very objective results. I have no such level professinal equipment like amirm, to measure differences, only my ears.
LME49720, original setup: sounds well, enjoyable, but at high volumes I found upper ends a bit metallic or harsh. Something could be better, so decided to experiment with output analog stage.
LME49720 +2*470u power rails caps: same as above but the upper end is smoother.
LME49860 +2*470u power rails filter caps: same as above, no differences heard, probably it'a identical to 49720.
OPA1656 +2*470u caps: the biggest difference! At first hear, it is crispier, fresh, cimbals are very vell defined. Very 'big' enjoyable sound. But, for complex instrumental music I found it grainy, bit annoying. Longer term listening found it fatique because this upper end bias and the lack of ability to handle complex music.
OPA1612 +2*470u filter caps: sounds so 'gentle' after 1656. Very vell detailed, no upper end emphasis at all, keeps all details. First, after 1656 sounds dull, but longer term it play real, neutral. With 1612 the sound stage positioned the best especially the center vocals. It keeps the music enjoyable at high volumes as well. This is my latest try, my favourite, I think will keep it for now. I like it's neutrality.
These are my objective results on my sound system, to my ears.
