Advice on hardware set up

this is my first time posting on this forum so I’m not too familiar with all the audiophile terms.
i’ave been using Roon for about 18 months and so far the experience has been great and at the same time a learning experience.
I have so many questions I would like to ask the knowledgeable staff and members, but first I’m trying to get my hardware correct or close to audiophile quality as my budget will allow.
so here’s my question, first of all let me state my audio chain.

Roon core server (running on unraid)
dac- toppin d50
preamp- Onkyo p- 3160
power amp- Samson 1200
speakers- Klipsch KFS 10.5
I also have an (APHEX 204) which use for time to time to manipulate the soundstage .

I’m thinking of replacing the Samson amp with a Onkyo 9050, I really love the Samson but I’m thinking the Onkyo would have a warmer sound signature.
or should I switch out the Onkyo preamp which doesn’t have balance input or output, I’m not sure!
I’m sure I will get the intel nuc soon for the rock core but for now I wanted to correct the main audio chain.
currently the system sounds fantastic but I know it can sound even better.
Any recommendation would be welcome.