I’ve been adjusting the setup on my Epiphone ES-335, following Justin’s series of lessons on how to do this, augmented by Gibson Gears YT videos on the same topics.
I’ve got the intonation set so that the open string and the 12th fret harmonic are in tune. But the fretted note on the 12th fret is either slightly sharp or slightly flat. I can’t seem to get all three in tune. I’m using a clip on poly tune tuner with a chromatic style display. I’ve varied my fretting band pressure to make sure it’s light as I can make it, just past the point where the note starts to get muffled.
The text in Justin’s video lesson (https://youtu.be/RB28OvzhybQ) indicates we should ensure the harmonic and a lightly fretted note are both in tune, but Charlie seems to compare the harmonic to the open string.
Appreciate any hints and suggestions.
(Perhaps it’s just the guitars way of telling me to buy a real chromatic tuner . )
Is the harmonic perfectly over the 12th fret? Is the 12th fret crowned properly?
My guess would be that the saddle is a touch off and the harmonic and the 12th fret are not aligned. Another problem could be that the 12th fret crown is not centered so not quite in the right place.
Hi Ashu, Tuners do play a big part in setting up however I use an istrobosoft tuner and it is very accurate, I also do a lot of setups and sometimes I struggle to get them perfect and sometimes even when I do and I go back after a couple of days it might be slightly out again, I think if you can get it as close as you can and it is not bad we can be happy. even slight pressure on your neck even the guitar’s own neck weight can change what we see good Luthiers have Jigs that hold the guitar in playing position perfectly so there is no movement at all when they set them up so if you can get it near enough be happy. cheers Hec and if you are worried lets look at your results no prons
If the harmonic is not the same as the fretted note, then your intonation is off. The idea behind playing the harmonic is to check the harmonic is not indicating the note is off. If you are off a little in the open tuning, the harmonic will look a little more off. No matter what, if you play the harmonic, it must be double the frequency of the open string - this is the way string vibrations must work in the physical world.
Trying to see where the harmonic is played by finger position won’t be easy to get accurate, so don’t try to use finger location.
If your action is set high, then you’ll have trouble because you are stretching the string to fret the note and it will be a bit sharp.
I have fiddled with how much the height of the pickup will degrade the tuning, and I can see it, but I did not find it to be large until I got overly silly about pickup height.
So, in general, you have not set your intonation, you need to make sure the string LENGTH is adjusted (at the bridge) so the fretted note is in tune. Adjusting the string length is effectively setting the 12th fret at the center of the vibration.
Thanks everyone, I will try adjusting again, compare the harmonic to the fretted note while ensuring the open string is in tune, and get as close as I can and will share a recording if needed. Appreciate the quick responses!
Edit:
Mike makes a good point about action and pickup height. I did lower my action slightly, and raised the neck pickup since it was a lot quieter than the bridge. But maybe I should have lowered the bridge instead.
Btw, a handy discoverey I made while setting pickup height by ear was that an Apple Watch’s noise app can serve as a volume decibel reader, for a secondary check of what my ears are hearing.
I have set the intonation on a couple of guitars. It’s sometimes difficult to get the note fretted at the 12th fret to be exactly spot on. However, if you are very close - ie the fretted note is only very slightly out of tune, then perhaps you won’t actually hear that it’s not intonated precisely. I’m not sure what our ear sensitivity is for whether a note is very slightly sharp or flat, but some tuners are really sensitive. So your tuner may show that it’s slightly off but you may not be able to detect that. So I think you should play the harmonic and then the fretted note and try to hear whether you can detect the fretted note to be out of tune or not. I have 2 tuners; one in my Orange Crush amp that is really not very sensitive. It can say that a note is in tune when it’s actually slightly sharp or flat and it’s possible for me to hear that the note is out. I have a separate tuner that’s extremely sensitive and when it says the note is very slightly sharp or flat, I can’t actually hear that the note is not in tune, ie the tuner is more sensitive than my hearing.
. )