I've inserted some recent compensated nuts into this post
so that you can all see my own evolution in refinement.
Above and below is a 1948 Martin
00-17 that I recently restored.
I first experimented with this idea 18 years ago with a 12-string guitar I had made for a customer. Since that time I have refined the technique and developed my own approach.
I hope you find this mini-tutorial useful.
In a nutshell .... the "G" string needs approximately 1.75 millimeters of compensation and the rest of the strings roll back from that distance.
I start the process by cutting the bone or "Tusq" blank,slightly oversized, then match the fingerboard radius and nut slot ( Fender style ) or the ledge ( Gibson style ) on which the nut rests.This operation is quite exacting and it would be well worth your while to purchase a blank from Buzz Feiten. Once I have the "1.75 mm extension" ( that overlaps the fingerboard) , I start the tuning process. Initially, I "take the nut out of the loop" ... by intonating ( at the bridge ) the 7th fret note and the corresponding 19th fret ( octave ) note, string by string, making sure that the instrument is tuned to concert pitch ( or whatever tuning the customer is using ). Once those pitches have been determined; then I go back to playing the open string and checking it against it's corresponding 12th fret octave note. If there are any discrepancies at this stage ; I'll gradually dial back (shorten ) the 1.75 mm nut extension bit by bit for each string, until the open and 12th fret notes line up.
There will always be very slight variations on this theme .... depending on the string gauge / tuning / scale length etc .... but I don't believe it is quite the "nano-science" that it is purported to be...
There is no doubt about it .... you will have to develop this skill to get precise and efficient.
There are manufactured nuts ( Buzz Feiten ) available. I've never tried any of these products myself; but these folks have really done their homework on the subject and offer pre-engineered nuts for the typical Fender and Gibson fretboard curvatures. It may be a good route to go for those of you who don't have the patience or the time to develop these skills that you'll need if you wish to make your own nut, from a bone / tusq blank.
After many experiments and variations, I have arrived at a system that definitely regulates the tuning across the span of the fingerboard to a much greater degree of accuracy.
I hope this helps to dispel some of the mystery .
Below, I've illustrated the 3-step process for a swamp ash
Gibson Les Paul nut.
When you compare the most recent nuts that I've done,
you'll notice that I've eliminated the obvious "gap-toothed"
look and have sanded , shaped and refined the nut so that
.... at a glance .... it just looks like a regular nut.
Below is a shot of a compensated nut I cut for a Gibson Songwriter
... very subtle ... unless I point it out
no one would even notice.
This is a guitar ( above ) that I built a few years back ... also with a compensated nut.
If you take a minute to check my
Page, you'll see a few more examples of the more refined compensated nuts.
Most customers with high end guitars .... ( Understandably ) ...
don't want to change "the look" of their guitars.
Pretty well every customer that I've done a compensated
nut for ... eventually returns with every guitar they own
for a repeat performance !
