More advanced information on Violin Setup

String height

At the bridge end of the fingerboard using a standard bridge curve, the string heights should be somewhere in the region of 4mm to 5.5mm at the G string and 2.5mm to 3.5mm at the E string, the lower values are used for steel strings, and the higher for gut and synthetic core strings.

At the nut end (peg box end) a useful guide is to take a good quality business card and slide it under the strings, if it moves under freely they are too high, if the string pinches it a tiny amount then it's about right.

String grooves at both ends should be semicircular and a little wider than the string, just deep enough to keep it in place. The grooves should never be 'V' shaped as this will trap the string causing tuning instability and possibly breakage problems, strings seldom just break, they will normally go either at the bridge, nut, or adjuster and most string breakage is caused by the string being pinched or trapped which causes overly high loads and damage to windings.

A useful trick is to take a HB or 2B pencil and rub it in to your string grooves, it helps lubricate and smooth them off allowing the string to move freely through. Also remember that gut/synthetic core strings are usually fatter than steel core, so you need to keep an eye out when changing string type that the grooves are big enough for the string.

Guitar setup

The range of string gauges available for the guitar, and different tunings can make things a little more complicated, even more so when you throw in the truss rod, but how the string should fit in the groove at the nut and bridge still applies.

The Truss Rod

The truss rod runs along the length of the neck, usually it is accessible from either under a plate at the head stock, or through the sound hole (on an acoustic). Tightening the truss rod will reduce the forward curve of the neck, slackening it will increase the curve. If you decide to adjust the rod there are a couple of things to bear in mind:

The strings actually do need some curve in the neck, the way they move means that at some point they will move towards the fingerboard when that happens without any relief you will get a buzz unless you have very high action, so having it dead flat or bowed back is really not an option, you can just about get away with it on an electric as pickups tend to lose some of the buzz, but in all reality the curve is necessary.

Small adjustments are the order of the day, 1/8 to 1/4 of a turn of the nut at the end of the rod maximum and allow a little while for the neck to settle. If you tighten the rod too much it may actually split the neck!

String Gauge

The instrument is designed to deal with a range of tensions, higher the string gauge the higher the tension. More tension means you have to push down harder, but generally produces more sound, lower tension will be easier to push down, but de tune more easily when you do push the strings down. When using tunings such as "drop C" there is a considerable drop in tension so a higher action is needed to stop buzzing etc that comes from the strings being able to flap about more (more tension=less string displacement) and it is probably going to be better to go up a couple of gouges to offset this lack in tension. If you are tuning a guitar in a non standard way, make your objective to try and maintain the relative tension between the strings, i.e. if you constantly have a string or two tuned down, put a higher gauge string on instead, it will help even things up and avoid the constant out of tune feeling you get every time you fret it!