If you are trying to make the guitar brighter acoustically then apart from puling the pickup away from the sytrings in case it is dampening the response , then you need to look at physical rather than electronic things.
Assuming that the strings are new as old strings will cloud everything
te only things that can make a difference to this guitar are :
Tuners
type of saddles
Colour of hardware - chrome/nickel WILL sound a bit brighter than black painted/coated
type of nut - it is here I will make my big point that if you have an Earvana fitted you may well get all the treble response that is possible from this particular guitar
Bringing the strings back in line harmonically in my experience adds both a sustain and a high end shimmer to the sound.
I wouldn't fit them to my own guitars if they didn't make such a difference
They allow me to get a Les Paul type guitar to be open, clear and responsive.
