Tweak it.
Buy yourself a spectum analyzer, thd meter,.......so on
Buy components like teflon caps, sikorels, golds.
Your pcb material is heard and it colorises the sound, find something better.
Nobody has yet attained sound Nirvana.
Foget all the above if u are satisfied with the sound of your system.
Sorry, now I myself is cofused.
Get into microcontrollers. It will keep u busy, especially if u don't know programming.
One thing is sure, enjoy what u do.
Gajanan Phadte