i wrote about this very same thing, quite some time back, and posted it here.
here's a re-post:
in my years of playing, and building the odd project here and there, the one thing that i consistently saw, was that if it sounded spanky without being plugged in, it'd sound spanky plugged in.
and if it sounded dead sitting in the shop, and if i plugged it in, dead.
(now, this is not to be confused with lots of gain, and radical tone shaping, and all that...
just the basic pure sound of the guitar amplified, versus acoustically playing it)
and i've switched out bridges and electronics, even nuts, and they all did do a little something....
but i think the magic comes from the 'tone' of the neck, and the 'tone' of the body.
and then the mojo is, marrying the two together.
when i researched and built my USACG project strat my luthier and i, had at our disposal, 5 strats in house, for sell or repairs or work....
3 fender strats of various vintage and country of origin (korean, MIM, MIJ)....
and 2 brand new american made strats.
we had my luthier's WARMOTH strat and neck....
plus, we had a few other strat wannabes-- Godin, Ibanez, the odd project guitar..
we did, at various points in the discovery process, take apart most of them.
one thing i noticed, was that certain 'necks' would not pass the 'tap test'.
what the tap test was, was simply hanging the neck (with all hardware off of it) from a hanger thru a machine head hole, and 'tapping' on the wood with the finger.
you could rap the back of the neck with your knuckle, and you could hear a distinct 'ring' or 'tone' in the wood.
every single neck was different.
some were solid maple, some maple with maple caps, some with rosewood caps....
all different.
as you would expect.
but some were dead sounding, and some were very lively.
needless to say, the 'lively' sounding necks, sounded the best on the bodies.
the bodies, a similar thing.
when i asked for my strat body, i decided on alder, and i specifically asked for the 'lightest 2-piece alder body' they had...
why 2 piece?
i don't know, i guess cuz the nicest body i found in the test, was a lightweight, 2 piece body that had a nitro finish on it, so that's what i patterned after.
i also had read a lot of articles on pros that had vintage strats, and that seemed to be a common thread.
when i got my alder body, while it was still raw, it had that 'tap tone'.
now when we experimented with various pieces at hand, you could hear the difference in the overall sound of the guitar (plugged in or not) when switching the necks out with different bodies.
also, the necks that had vintage style truss rods (one of the reasons i went with the USACG necks over the warmoth necks) was another big 'aha'.
it seems that, the way the wood is cut, and how the truss rod was installed, made the biggest difference of all, over wood types and fingerboard selection...
i took a maple/rosewood warmoth neck, with a gibson conversion scale, the double expanding truss rod thingy (which really makes the neck heavier and somewhat dead sounding) and a/b'd it against my freshly minted USACG neck with rock maple neck and pau ferro fretboard, basically the same neck as the usacg, except for the truss rod and the fret wood.
no contest.
my neck had the 'tap tone', and the warmoth did not.
plain and simple.....
i was absolutely convinced.
another difference BETWEEN my neck and the warmoth i compared to, in particular was the construction of the 'tiltback' headstock.
the usacg uses a volute construction...
the warmoth used scarf joint.
that seems to have some bearing as well.
moral of the story....
it's gotta be the wood.
