The typical nut on a classical guitar is 52mm wide and has slots cut in it to give string spacing somewhere between 42mm and 44mm.
If you find this too wide for comfort you can change to a guitar with a narrower nut width (and with this narrower string spacing).
An alternative is to have a new nut made with narrower string spacing. There are two approaches to this
- increase the distance between the outer string slots and the edge of the neck/fingerboard and reduce the spacing between all 6 slots. The possible disadvantage of this is that the space between the outer strings and the edge of the neck/fingerboard my feel uncomfortable – particularly on the treble side.
- Keep the distance between the new slot for the first treble string the same distance from the edge of the neck/fingerboard and then close up all the other slots; this results in all 5 lower strings being positioned further away from the bass edge of the neck/fingerboard, particularly noticeable on the lowest bass string which will have an unusually large gap. This should not be a problem (once you are used to it) unless your style of playing involves using your thumb to fret the lowest string – more typical of a blues style of playing than a classical, but it definitely suits some players.
There are two financial advantages of changing nut rather than changing guitar: a nut is much less expensive than a new guitar, and it is easy enough to put a standard nut back if you want to sell the guitar and you are then selling a “standard” model which is often easier than selling a custom instrument.
It is a relatively easy job to change nuts – sometimes they are unglued and just lift out, sometimes they are held in with a very small drop of glue and can be tapped out. Best check with the guitar maker before you take a hammer to the nut, just in case it is fastened more securely than usual.