Intonation question: Open string and 12th fret in tune, 5th fret sharp.

[NoahL]

I haven't had time to check to see if this is a problem across all strings, sorry. It showed up last night after a string change and a quick intonation. I fear that I don't do the intonation the best way -- just open and 12th fret depressed. How do I incorporate the harmonic into this? And what about that 5th fret that's sharp? This was on the G string and I'll check the others tonight, plus at other spots on the neck. I know intonation is a compromise, but this seems wacky.

[Hargrett]

How did you determine that the G string was sharp at the fifth fret?

[NoahL]

That's what my Korg stompbox tuner said. It read a couple red dots north of in-tune.

[Hargrett]

If the G string read "in tune" from open through the fourth fret, sharp at the fifth, and "in tune" all the rest of the way up, that's a strange one... the first thing I'd try is a new G string.

[Rosewood]

Be sure to fret it many times to make sure you have a good average reading.

[Scumback Speakers]

Sounds to me like you have too much relief in the neck, forcing you to press down the string too far at the 5th fret, thereby causing it to read/sound sharp.

[Hargrett]

If the G string read "in tune" from open through the fourth fret, sharp at the fifth, and "in tune" all the rest of the way up, that's a strange one... the first thing I'd try is a new G string.
When adjusting intonation, I think a lot of folks tune the open string, check the harmonic at the 12th fret, gently fret the string at the 12th fret, check the tuning at 12, and adjust the bridge saddle accordingly. There are other adjustments that may need to be made for the guitar to be intonated correctly... it's not all in the bridge, by any means.
If your guitar is playing in such a way that you feel you need to check each note with a tuner (a sure formula for frustration), the best bet is probably to take it to a shop for a set-up, including truss rod adjustment, fret level and crown, nut dress, bridge adjustment (height and intonation), and pickup adjustment. After all that, it should be as good as it's going to get. All the best!

[EADGBE]

Try getting the harmonic at the 12th fret to sound exactly in tune to the string fretted at the 12th fret and both of these exactly one octave above the open string using your ear. I don't think Korg tuners are very accurate. Do this in a quiet room and take your time.

[walterw]

Originally Posted by Hargrett

If the G string read "in tune" from open through the fourth fret, sharp at the fifth, and "in tune" all the rest of the way up, that's a strange one... the first thing I'd try is a new G string.

yep.

Originally Posted by Southbay Ampworks

Sounds to me like you have too much relief in the neck, forcing you to press down the string too far at the 5th fret, thereby causing it to read/sound sharp.

+1, or the nut might be too high, causing the same problem that too much relief would cause on the first few frets, and especially on a plain G.

[forestryguy]

Could also be a string guage problem if it was intonated for one guage and another was used. Particularly if it was a plain 3rd replaced with a wound one.

[NoahL]

Originally Posted by EADGBE

Try getting the harmonic at the 12th fret to sound exactly in tune to the string fretted at the 12th fret and both of these exactly one octave above the open string using your ear. I don't think Korg tuners are very accurate. Do this in a quiet room and take your time.

this isn't one of those $20 Korgs. it's the $100 stompbox type. is that still unreliable? does Korg have a bad rep? i guess that brings up the question of what is the cheapest really good tuner for intonating?

[welcometoashley]

Originally Posted by NoahL

this isn't one of those $20 Korgs. it's the $100 stompbox type. is that still unreliable? does Korg have a bad rep? i guess that brings up the question of what is the cheapest really good tuner for intonating?

i have better results setting intonation with a strobe tuner (like a peterson). never tried a korg, but i tried setting intonation once with one of the boss tu-2's and it was not helpful at all...

[Super Locrian]

A guitar tech told me that you either have to use your ear or a strobe tuner to intonate a guitar properly. Regular tuners are neither precise nor consistent enough. And it's not just a matter of adjusting at the bridge, you need to adjust the truss rod for the right neck relief as well.

[Hargrett]

... and if the nut slot angles aren't cut right, you won't get the intonation right by adjusting the bridge...

[gtrnstuff]

Is it only the 3rd string? Time for a new string. I've had good brands that have a bad one in the set, brand new.

Try comparing 1st fret to 13th, intonating the bridge. That takes the nut height/location out of the equation. Then check the middle frets.

Most tuners in the $100 range will do an acceptable job. My Peterson Virtual Strobe reads faster and more accurately, but I get OK results with Korg DT-7.