Guitar Setup

Started by Elantric, April 23, 2014, 08:14:29 AM

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Elantric



Setting Up Your Guitar

Adjusting the Truss Rod

The strings of a guitar exert a tremendous pressure on the neck. As tuning knobs are turned to tighten strings, the increasing tension tends to force the neck to curve away from the strings. The effect is similar to stringing a bow for archery. The major difference is that a guitar neck has a truss rod inside to resist the pressure for curvature. Over years, the neck alignment can change, and you can detect change visually and by feel. If low action playability has suffered and more pressure is required to fret the strings, the problem could be neck alignment. Hold the guitar so that you can see the clearance between strings and frets down the entire scale. If the neck appears to be either curving away ("cupping") or too close to the strings in the middle, the truss rod needs adjustment.
Most quality guitars have a truss rod which allows adjustment of the neck. The rod may be accessed either under the truss rod cover on the headstock, or on the base of the neck. The rod assembly is a metal rod inside a plastic sleeve. The rod is threaded at the top end and has a nut which can be tightened or loosened. Tightening the nut in effect shortens the rod and pulls the neck closer to the strings.
Loosening the nut makes the rod longer, and the neck clearance from the strings increases.
Adjustment should be made only when necessary. The result of proper adjustments will be a perfect neck alignment for the life of the instrument.

Intonation
Intonation is the ability of the guitar to maintain tune the entire length of the scale. Accurate intonation is critical to sound quality. There is a simple test for it, and the guitar doesn't even have to be in tune.
The twelfth fret of the fingerboard is the middle of the scale. When the string plays the same note open and fretted at the twelfth, intonation is in adjustment. To make intonation as accurate as possible, plug into a meter rather than trusting your own ear. If the instrument has good intonation, you will know it from this test.
Depending on the physical makeup of the guitar, intonation can be adjusted at the bridge, and with the adjustable truss rod inside the neck.
Adjusting the truss rod or even changing strings on the guitar can change intonation. These alterations will possibly change the length of the strings, and even minute changes can diminish the instrument's intonation.
With some bridges, adjusting the length of the string is simple. Each string has its own saddle with an adjustment screw which moves the saddle forward and backward on the bridge.

Basic Guitar Setup

Put on new strings. String action (height), fret buzz and intonation will vary with different string gauges and from old to new strings. You want to do your setup under actual playing conditions, so string your guitar with the gauge of strings that you're going to play. If you're replacing strings on a new Gibson, most solidbody electrics (Les Pauls, ES-335s, Nighthawks, Flying V's, SG's) come from the factory with light gauge strings, beginning with .009. The Chet Atkins SSTs and hollowbody electrics (ES-175) come with .010s. Most flat tops are strung at the factory with medium gauge, beginning with .013.
Tune up. Again, your guitar needs to be in playing condition, so tune up to standard pitch (or whatever tuning you'll be using).
Check the straightness of the neck. Use a straight edge to determine if a truss rod adjustment is needed. If the neck is bowed, there will be a space under the middle of the straight edge where the neck does not touch the straight edge. If the neck is "backbowed," the frets will touch in the middle of the straight edge.
NOTE: A slightly bowed neck is ideal for most playing styles. A perfectly straight neck generally requires higher string action than a slightly bowed neck in order to minimize string buzz at the higher frets. Repairmen describe this as giving the neck some "relief" to allow for string vibration. The amount of relief necessary varies with playing styles, however. A perfectly straight neck may be fine for a very light picking style. If your neck has only a slight bow, you may not want to make any adjustments to the truss rod.
Adjust the truss rod (if necessary). First remove the truss rod cover. If the neck has too much of a bow, then the truss rod should be tightened with a clockwise turn of the nut. For a clockwise turn, the arm of the nut driver should start on the treble side of the fingerboard and move toward the bass side. Don't turn the nut more than a quarter of a turn at a time. For a backbowed neck, the truss rod should be loosened with a counterclockwise turn of the nut. When the neck is as straight as you can get it, then back off about a quarter of a turn for "relief."
Check string height. With the small ruler on top of the fret, measure the distance to the bottom of the string. (You can also use a feeler gauge for these measurments.) The string height at the 1st fret will determine if the nut slots have been cut to the proper depth. If the nut slots need to be deepened or filled in, that's a job for a pro with the proper tools.
The string height at the 12th fret will determine whether the saddle should be raised or lowered.
Gibson electric specifications are:
1st fret- treble side - 1/64"
1st fret- bass side - 2/64"
12th fret- treble side - 3/64"
12th fret - bass side - 5/64"
Adjust saddle height. On an electric guitar with a tune-o-matic bridge, the thumbwheels will raise or lower the bridge. You may have to loosen the strings a bit to get the bridge to raise easily. To lower the nut slots, special nut files are required that are available from guitar shop supply sources. You can get them from Stewart-McDonald. Set nut slot depths to specs listed above for first fret.
Check for fret buzz. Using a medium pick or light finger touch, check all fretted notes for string buzz. If correct, move up the next step. If not, some fret leveling may be required. This is another procedure for a pro with the right tools.
Check intonation. At the 12th fret, play a "chime tone" by touching the string without pressing it to the fret. Release your finger from the string as you pluck it. You should hear the octave overtone. Now press the string to the 12th fret and play. If the tones match, then the intonation is correct. Notice that the 12th fret tone may vary according to how hard you press the string down.
Adjust intonation. On an electric guitar with a tune-o-matic bridge, the length of each individual string is adjustable. If the 12th fret tone is higher than the string's natural octave overtone, then lengthen the string by moving the saddle toward the tailpiece of the guitar. If the 12th fret tone is lower than the octave overtone, then move the saddle toward the neck. On an electric guitar with a wraparound tailpiece, the tailpiece can be adjusted only at the treble end and bass end. It is usually not possible to achieve perfect intonation for every string with a wraparound tailpiece. If an individual string is out of tune, you may be able to compensate by replacing that string with a higher or lower gauge string.
Advice. If you want to attempt some of the more advanced setup and repair procedures, such as fret leveling, neck set or saddle replacement, first arm yourself with the proper instructional and proper tools, then try your hand on a junker guitar before you attack your favorite instrument.
Information provided by Gibson Guitar Corp.

Gibson Truss Rod Information


For Fenders:

http://support.fender.com/manuals/in...29_English.pdf
Fix a capo to the first fret, then fret the sixth (low E) string at the
last fret. Then measure from the bottom of the string to the top
of the 8th fret—the gap should be about .010". Plus, when you
eyeball the neck by sighting down it from the body end toward
the headstock, you can see whether the neck is straight or
bowed (and you look really cool when you do this).
Fender guitars use two kinds of truss rod adjustment
mechanisms. One is accessible at the headstock and adjusted
using an Allen wrench; the other is accessible at the neck joint
and adjusted using a Phillips head screwdriver. For both types,
here's what you do:
Adjustment at headstock (Allen wrench):
If neck is too concave

(the guitar in playing position, looking up the neck towards the
keys) turn the truss-rod nut counter clock-wise. Too convex -
clockwise.
Adjustment at neck joint (Phillips screwdriver): If neck is
too concave, turn the truss rod nut clock-wise. Too convex
-- counter clockwise. Check your tuning, then check the gap
again with the feeler gauge.
That's it. You can double-check your adjustments by sighting
down the neck and by measuring that gap again to make sure
it's around .010". Never force a truss rod !