DIFFERENT KIND OF GUITAR HEADSTOCK
The headstock too plays a sensible role in the tone of an instrument.
The most rigid is the neck/headstock joint the more the headstock will return intact the strings
vibration to the neck so the better the vibration and the longest the sustain. On the contrary,
if the headstock tends to flex it will absorb vibrations and sustain will be affected.
There are basically two ways of building a headstock: straight or angled.
Both have an impact on tone, reliability, playability and cost of production.
Typical Fender headstocks (Strat/tele/JB etc) are named "straight". This type of construction allows the neck and the head to
be made out from a single piece of wood about 20mm thick.
This solution allows a considerable spare in time, rejects and production costs and fits a mass production runs. It's normally matched to a 6 in line tuning gears placement and it's therefore very suitable for guitars equipped with tremolo due to the reduced friction point of the strings over the nut and the fact that they runs straight over it with no side angle.
On other types of instruments just like Gibson for example, the headstock is angled (tilted) and requires a major investment and wood
material with a consequent rising of the manufacturing cost.
An angled headstock also offers a much weaker resistance to shocks due to the reduced length of the grain in the joint area.
For the above weakness reason some manufacturers has adopted a solution typical of the classical guitars luthiers, the scarf neck.
To build a scarf neck the original piece of wood is cut in two pieces along its length and the two pieces are then shaped and glued
together like in the above picture so that they recreate the typical angle of a tilted back headstock (picture 2) allowing a much
higher resistance to mechanical shocks still retaining the same tonal advantages and tone of the angled head.
HEADSTOCKS AND TREMOLOS
Generally tilted back" headstocks are are used with fixed bridge while the straight construction better conforms to the tremolo use due to
the straight alignment of the strings it allows over the nut which reduces the friction and favours the strings sliding for as shown in
this series of videos where Galeazzo Frudua explains all kind of
modifications you can apply to you tremolo equipped guitar to achieve a perfect tuning stability.
Other manufacturers like for example PRS has achieved fine results in this sense even with tilted back headstocks by reducing the angle from the standard 15 degrees of the LP to 10 degrees and re-designing the tuning gears placement so that the side angle is strongly reduced. All those modifications has the result to reduce the friction of the strings in the nut area thus improving the tuning stability.
Both the "straight" and the "tilted back" design allows a Floyd Rose nut to be mounted
even if it's necessary to verify that it does not interfere with the truss rod adjustment nut especially in the straight version.
resistance to mechanical shocks.
HINTS AND TIPS
Adding any kind of "mass" to your headstock may contribute to improve your tone and avoiding "dead" notes.
stiffness and mass thus improving tone and strings vibration.