The most critical parts when recapping

I've done some recapping, but I realize I don't know what parts are the most important. I'm doing this on the basis if just replacing cheap caps with good/great caps; I want to increase sound quality. But there's a ton of caps, both larger and small.

If we limit this to integrated amplifiers, what are the most important for sound quality? All of them? Preamp caps? Power caps? Small, large?

What other parts are a big deal, like resistors? And are there rules of thumb for what that makes the biggest difference, or is this completely up to the design, or is it always the whole of it?

Showing 2 responses by eyrepm

Thank you both for great input! This really cleared it up for me. 
About diodes:
Do you also here look for the same "values"? Or are there aspects to them that you can change?

Luckily, in my project now, I actually have replaced the large power caps, and a set of four around them. There are a bunch of tiny caps, like 10uf 50v. Worth swapping out?

Would one be able to tell if this is a coupling cap? It is a Wima Series 4, 0.1uf 250v.

This is a Schiit Ragnarok 2. I’ve seen others switch out Wima film caps in Schiit products, with good results. Those were tube preamps though.