Intonation

Started by FreeTime, July 07, 2017, 04:38:58 PM

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FreeTime

I changed string gauge on my guitar yesterday so I checked the intonation. There are a couple of different camps on how to do this, some people like fretting the note, others like pulling a harmonic, I'm not sure which is right since both parties say theirs is the correct way. My guitar has fairly high action so I can really grab a note; I prefer pulling a harmonic so I don't put tension on the string by fretting it, making the string go sharp.

I kept at it: tuning, checking at the 12th fret, adjusting, and retuning until each string was perfect. Then I checked the harmonics on the 7th and 5th fret. To my surprise some were a bit sharp, others flat. I did tiny tweaks to bring those into tune, it took less than an eigth of a turn to overshoot, until all was good again. Now my guitar is intoned all over the neck and rings better than ever.

Elantric

#1


The whole point of adjusting the string intonation is to compensate for the fretted pitch registration or String type / gauge, Guitar Action, and Playing technique.

In summary

"Your harmonic on the 12th fret and the fretted note on the 12th fret should both play at the same note--neither sharp nor flat"
http://www.guitarrepairbench.com/electric-guitar-repairs/adjust_intonation_electric_guitar.html

1) observe the players desired String type, and string gauges are installed 
2) observe fret type and fret height, or scalloped fretboard of the instrument


3) Adjust String action,
     * Adjust Truss rod
     * Adjust string height at Nut,
     * Adjust string height at bridge
      * Adjust the pickups ( magnetic flux =  strings pulled sharp if Strat neck PU's set too close) 

4) Tune the guitar to the default open string tuning ( A:440hz, vs Eb Tuning vs Baritone tuning, vs DADGAD vs?) 

5) If intonating someone else's instrument its crucial to Observe the players typical playing touch downward torque pressure applied to the strings while fretting and playing technique  - this plays a huge role on proper intonation particularly if the fretwire is tall Dunlop 6100 type or scalloped fretboard is employed on the instrument  -= some players with heavy handed technique will play notes sharp vs a light touch player. Failure to take this into account might spell disaster if setting up someone else's guitar

( for example, Stevie Ray Vaughan had a fairly heavy touch, while Steve Vai has a very light touch. a good Luthier takes this element into account when setting up the guitars intonation 


6 )I establish all 5 points above are fully understood and guitar action is set to desired settings BEFORE I touch or adjust the bridge saddle intonation screws!

when I do the intonation step ,

7 )  I tune the guitar to the desired pitch  open A= 440Hz with a Peterson Strobe Tuner

8 )  I start with the high A string and hit the 12th fret harmonic - and verify the string is 880Hz

9 ) I fret the A string at the 12th fret with my typical fretting pressure, and verify the fretted note = 880Hz
      * if fretted note at 12th fret is sharp ( higher than  880Hz) I adjust the bridge saddle closer to the tailpiece and repeat from step #7
      * if fretted note at 12th fret is flat ( lower than  880Hz) I adjust the bridge saddle closer to the neck and repeat from step #7

10 ) After the A string Harmonic at 12th fret pitch 100% matches the fretted note pitch at the 12th fret, I perform similar steps for all other strings. Often this means going back to Step #3 for each subsequent string being intonated until all strings have been verified that the fretted pitch at the 12th fret 100% matches the "unfretted" 12th fret harmonic pitch.   
 

https://www.youtube.com/watch?v=NEjekEOMWmg&list=RDNEjekEOMWmg#t=701

mooncaine

Good steps in the detailed post above. When I'm done doing those, I compare the fretted and harmonic notes at the 19th fret, too. Job's not done until those match.

Elantric

Quote from: mooncaine on July 07, 2017, 05:40:59 PM
Good steps in the detailed post above. When I'm done doing those, I compare the fretted and harmonic notes at the 19th fret, too. Job's not done until those match.

Good point

I also compare the fretted note at the seventh fret is an octave below the seventh fret harmonic