The neck relief is the “bend” that the neck has. It is not supposed to be completely straight as when the strings vibrate the would hit the frets. A poorly adjusted neck relief leads to fret buzz. Recently I switched to a thinner set of strings (9-42) from what I usually play with. The tension that the new strings made on the neck were less than the previous strings, creating too much relief in the neck, this lead to fret buzz and I couldn’t even play on the higher frets since they did catch the high frets completely. In order, to fix this I had to tighten the truss rod on the guitar.
In order to set the correct relief, I used the “Truss Rod Gauge” from MusicNomad. You tune the guitar, set a capo on the first fret, hold down the 12th fret. Then you use the 0.006inch/0.15mm gauge to feel between the string and the 6th fret. The gauge should barely touch both the string and the fret.
For a great explanation see this MusicNomad Video.
The string action is the height of the strings to the frets. If they are too low it can lead to fret buzz and if they are too high it can be awkward playing. In order to set a good string height I use the MusicNomad String Action Gauge. I set a capo on the first fret, and then measure the string height at the 12th fret. On my guitar I currently have approximately 0.07inches/1.75mm on the low E string and 0.06inches/1.50mm on the high E string.
For a great explanation see this MusicNomad Video.
On my Les Paul I can adjust the height of the tail piece/stop bar, where the strings attache behind the Nashville bridge. I set this height such that the strings do not touch the bridge after the highest point (where they are supposed to touch and stay in place).
The pickups should be correctly adjusted to give a balanced sound between the pickups, such that the volume is levelled. The MusicNomad’s String Action Gauge has a pickup ruler as well that I use. On my Gibson Les Paul Special SL I follow their instructions that have the bridge pickup at 1/16th of an inch and the neck pickup at 3/32nds of an inch.
For a great explanation see this MusicNomad Video.
As a last step it is important to intonate the guitar, such that the strings are in tune all over the fret board and not just at the open string. One good method here is to tune the open strings, then play at the 12th and the 17th fret and adjust the bridge such that these notes are also in tune.
If it’s a bit sharp you pull the saddle back a bit. If it’s a bit flat you pull the saddle forward a bit.
Remember that all guitars are different and that some guitars cannot be exactly in tune all over the fretboard. For example, Gibsons have a tendency to run a little sharp in the upper frets. One idea here is to perfectly intonate the low E, A, and D strings at the 12th fret, as we don’t usually play much there.
One additional tip is, if your tuner has problems to fully catch the notes you’re playing you can turn down the tone nob all the way on the guitar.
For a great explanation see this MusicNomad Video.
There are several other things that are important on a guitar, such as the frets and neck angle. However, what has been discussed in this blog post are the simplest adjustments that every guitar needs to get right, and if there aren’t any more severe problems with the guitar these adjustments should be sufficient for an excellent tone.