Intonation Regulation
by Glenn Letsch
reprinted by permission
Electronic Musician Magazine
Knowledge of effective tuning techniques is one of those things that separates the amateur players from the pros. There's more to it than just kicking down $80 for your basic guitar tuner and tuning up. Once you learn how to get your guitar or bass in tune and make it stay there, you can deal with the easy stuff, like blinding chops and impeccable taste. Stringing along. Good tuning starts with quality strings. Not all strings are created equal. The overall gauge may be the same between two sets of strings, but one brand may have a smaller center core (like DR Strings), so they will behave differently. Similarly, stainless steel and nickel strings will not intonate the same way. Whatever type of strings you favor, find a brand that offers consistent quality and stick with it. You'll do less tweaking in the long run. Most guitarists find that heavier-gauge strings hold their tuning better than lighter ones. There are exceptions, including James Burton, guitarist for Ricky Nelson and Elvis Presley, who has made history using 0.008s. Burton pulls it off with a great ear and very light touch-mere mortals beware! Lube 'em up. Before you start stringing your bass or guitar, lubricate the nut slots with pencil lead or automotive graphite powder. Over time, a string's windings will create tiny divots in the nut slots, and the graphite will keep the string from catching on those divots. If your guitar has string trees, dab some Chap Stick or Vaseline under the tree "wings" using a toothpick. You should also check to be sure that your nut slots are cut wide enough. If the slot is too tight and is pinching the string, you will hear a "plinking" sound while tuning. Find a competent guitar tech or widen the slot yourself by carefully filing it with a wound string or a proper nut file. All wound up. Some guitarists make the mistake of not attaching their strings to the tuning pegs securely. To put a new string on your guitar, stick it through the peg shaft, and then wind it toward the center of the peg head, halfway back around the shaft. Next, guide it under and over itself. On guitars with locking pegs, pull the string tight through the peg before tightening the set screw, but do not overtighten the screw. In either case, trim the excess only after you've bent or locked the string. Otherwise, the windings will come loose. Securing strings properly is just as important on a bass. Wind counterclockwise on a Fender-style headstock; on a two-plus-two bass headstock, wind the E and A strings counterclockwise and the D and G strings clockwise. Cut any excess length from the string. Next, shove the string down the center of the post and wrap it downward. As you tune up, the tension will draw the string down and prevent it from slipping out of the nut. You want to have as few string winds on the peg as possible. If the windings overlap, they will cause the strings to "slack out" as you play and slowly go flat. On a guitar, allow no more than two or three winds for wound strings and three or four for unwound strings; on a bass, wind each string approximately three times. Quality control. Once the strings are installed correctly, check for defects by observing the plucked open strings. Use this technique with caution when you're under fluorescent lights. These lights flicker at a rate of 60 times per second and create a strobe effect when you observe a vibrating string. As a result, a good string may appear to vibrate erratically. However, any string that vibrates erratically under incandescent light may have loose windings and should be replaced. Tune up, stretch out. Always tune up going from flat to pitch. Never tune from sharp to pitch because the string will bind up on either the post or the nut and go flat when you start playing. Believe it or not, a lot of folks forget to stretch new strings. With a soft cloth wrapped around your thumb and index finger, gently stretch each string every few inches up and down the neck. Retune. Repeat. Retune. Repeat. It may take a few yanking sessions, but keep it up until the strings stay in tune. Intonation. Intonation is simply the process of adjusting the length of a string so it is "in tune with itself." Each open string must be in tune with its octave at the twelfth fret. Granted, the laws of physics and the rules of equal temperament determine that your instrument can never play perfectly in tune all over the neck. But with the right equipment, you can get pretty darn close. In order to be dead on the money, most luthiers recommend using an electronic strobe tuner or equivalent. A regular, inexpensive tuner won't be as accurate. The strobe tunes within one-third of one percent of a semitone. The newest models from Peterson Electro-Musical Products (tel. 708/388-3311) are even more accurate (one-tenth of one percent of a semitone). Old strings can be very difficult to intonate. Strings lose their uniform consistency as well as attract hand oil and dirt. Frets also put small dents in them. So buy new ones as needed. First things first. According to luthier John Jordan of Jordan Music ( based in Concord, California), "Intonating is the very last thing you do when setting up your guitar because everything affects intonation. Be sure to make all other necessary adjustments first. Any later changes that you make will invalidate the intonation process." You may want to adjust the truss rod to attain proper neck relief or move the bridge for proper string height. Your playing style (aggressive or light) will dictate the correct settings. Remember to adjust in minute increments. You do not want to blow past the ideal settings for your playing style. Work it until the action feels right; then, and only then, begin to intonate. It is important to recheck your intonation every couple of days because strings tend to go flat with age. When you intonate, be sure that your guitar is in its usual playing position. Don't lay it flat on its back unless you're Jeff Healey or a Thumbs Carlisle impersonator. Otherwise, when you go back to your usual playing position, gravity will skew all your careful adjustments. Reasons to fret. With the instrument tuned to pitch, pluck a twelfth fret harmonic and compare it to the actual fretted note on that string. Be sure to use just enough finger pressure to sound the note clearly. Avoid pressing the note sharp. If the fretted note is flat, the string is too long and the bridge saddle must be adjusted forward. Turn the saddle screw counterclockwise to shorten the string and raise the pitch of the fretted note. (You may need to force the screw inward as you turn because it can get stuck when loosening.) If the fretted note is sharp compared to the harmonic note, the string is too short. To lengthen the string, adjust the bridge saddle back slightly by turning the screw clockwise. Retune the string to pitch and compare and adjust until the fretted and harmonic notes agree. Now adjust the rest of the strings. The twelfth-fret system covers the needs of most guitar and bass players. But if you frequently play above the twelfth fret and find that the pitch is off, you can fudge your intonation a bit. Shift your intonation point from the twelfth to the nineteenth fret, and then proceed as above. Fretless bass. When you intonate a fretless bass, it is crucial to use proper fingering technique. Place the center of the end of your finger pad just behind the twelfth fret line. The point of contact should be just in front of the center point of the finger (the front third of the finger). Jordan advises, "Do not straddle the middle of your finger over the fret line. The string will make contact in front of the fret line, so you will be playing the note sharp." If you own a fretless bass that does not have fret lines, intonate using the midpoint of the double-dot octave marker on the side of the neck (twelve semitones from the nut). Magnetic attraction. Make sure your pickups are not too close to the strings. Their magnetic fields can pull your strings sharp and deaden string vibration, killing your sustain. Check the distance between the pickup pole pieces and the strings by fretting the highest and lowest strings at the top fret and sighting across the guitar. Seymour Duncan recommends adjusting single-coil pickups at least one-sixteenth of an inch away from the string on the treble side and one-eighth of an inch on the bass side. Humbuckers, with their more diffuse magnetic fields, are slightly more forgiving. In Tune Outdoors. Gigging outside can be very tough on tuning, especially in direct sunlight. To avoid problems, always gig with a tuner hooked up to your signal chain. You can use an A/B box or a dedicated parallel tuner output from your amp to check your tuning quickly and silently. This ensures pristine tone by removing the tuner from the signal path when it is not in use. Besides messing with your tuning, the bright light of a daytime, outdoor show can make it nearly impossible to decipher the LEDs on most tuners. You can try constructing a "tuner tent" out of a cardboard box to shade the display. Whether you're playing indoors or outdoors, try acclimating your guitars to the venue's temperature for at least 30 minutes before the gig. Strings tend to expand or contract when confronted with sudden changes in temperature. Steve Miller tours with graphite and composite-neck guitars because they resist temperature and humidity changes. Tuning out. Playing in tune is the result of many small steps executed properly, and adding even one or two new tricks can make a big difference in your quest to play and stay in tune.