Neck isn't warped, nor back-bowed.....

[Newc]

...but for some reason my strings go sharp. Like, up a half-step or more. All of them at once, not just one or two.

Neckthrough, stringthough, tuneomatic, Sperzels, bone-ish nut, maple neck, ebony board.

If the neck's not warped/twisted nor bowing back, what could it be?

[murkat]

On the neck, at what fret does it go sharp?
detune?
Intonated?

[Newc]

All of them. It's like the neck is bending backwards, but it's not moving.

Tuned to A=440, intonated as well as can be done in a guitar.

I can tune them to standard E, then let it sit for a few days and the strings have all increased in pitch.
Open notes, not just fretted. Like it's growing. Maybe my guitar is getting wood?

[Rich#6]

Bridge moves? or is the truss rod messed up?

[DonP]

High nut? Taken to the extreme, if your nut was an inch off the fretboard, by fretting a string, you would stretch the string sharp.

Other than that, nut in the wrong place? Frets in the wrong place? Bridge in the wrong place?

[Axewielder]

Was the truss recently adjusted? Sometimes those can take a few days to settle out.

[LouSiffer]

Mine dies this all the time Newc. Its an unfinished maple/maple neck with a floyd locking nut. I have had many guitars do this. The neck is expanding in length due to temperature or humidity changes. -Lou

[Newc]

But it only goes up, never down.

It's not an issue with any fretted note; the open low E goes up to F#, and all open notes follow accordingly, so that rules out the nut height.

The neck is flat/straight, neither concave nor convex.

The frets are not lifting.

The nut and bridge are in the right spot.

Since I've owned the guitar (almost 4 years), I have only ever had to loosen the rod, and it's completely slack. I have never once had to tighten the rod.

Most of all, it's a Custom Shop, rumored to have been in the hands of Grover himself during at least part of the building, so I'm not quite ready to believe it's a question of workmanship.


The guitar has no tonal or playability issues, just this one quirk, which I've learned to compensate for by retuning whenever I use it. However, it would be nice to know what's causing it.
No other guitar I've ever owned did this, and I've had some that were absolute shit


Even though it's an oiled neck, since the neck never flexes forward, that should rule out changes in humidity.

I've often thought of putting 10's on it for a while to see if they either snap or cause the issue to correct itself.

[Axegrinder87]

I'm no expert by any means, but if the truss rod is completely slack, then it's not doing it's job in EITHER direction. I say tighten it until it's just snug, without actually inducing any backbow.

[Chad]

Clearly, something is moving. To clarify, are you saying it's fine while playing, but this only happens when it's been sitting for awhile, then you pick it up? Where is it stored when not in use?

[DalyTek]

I'm no expert by any means, but if the truss rod is completely slack, then it's not doing it's job in EITHER direction. I say tighten it until it's just snug, without actually inducing any backbow.

I'm with Axegrinder here. With the truss rod completely slacked off, you've got enough play in there to allow the neck to flex much more than it should. Snug it up and that might actually be enough to stop this weird phenomenon.

[Chad]

I'm with Axegrinder here. With the truss rod completely slacked off, you've got enough play in there to allow the neck to flex much more than it should. Snug it up and that might actually be enough to stop this weird phenomenon.

If the relief is as desired with the rod loose, then all that's gonna be accomplished by snugging it is preventing the truss rod nut from rattling. The rod wouldn't actually be doing anything. Older guitars (Martins acoustics, for example) didn't even have truss rods and they didn't exhibit this kind of phenomenon.

With that said, for a guitar to go up in pitch by a half or whole step, the neck would have to be backbowing to a rather large degree. And NewC says that it plays fine after tuning it up. Further, he has said that the neck stays straight.

All of this points to it not being a truss rod issue. Sidenote: truss rods are the remedy for everything on guitar forums. Truss rod adjustments will apparently remedy everything from fret buzz to headaches. If a person is having a bad day, they should try adjusting their guitar's truss rod. It might be the cure.

Anyway, I'd be looking at a possible loose nut or bridge. Although, those issues would happen during playing.

[Nimitz]

Maybe someone is playing a joke on you and tuning your guitar up while you sleep.

[horns666]

I install a marshmallow Peep in all my trem cavities. Never touched truss, saddle nor screw since. They also expand/contract to counterbalance ALL temp/humidity issues.

Stop playing the Iron Man intro wrong...that's what's doing it.

C'Ya Matt...you'll figure it out!

[Newc]

I'll route a trem cavity into it and squeeze a Peep into it - maybe that'll fix it. Thanx Billzebubba


Axe: Getting it snug makes it bend back.

Chad: Since I don't play for hours on end, I can't say if it does it while playing. I play it for a bit, then put it up for a couple of days, then grab it again and it's whacked. It hangs on the wall when not in use. No kids in the house, no one else screwing with it (due to my Clutter Barrier that scares people away )


The intonation doesn't fluctuate when playing, so it can't be the bridge or nut. I've had the strings completely off and the nut stayed on, so it's on there correctly.


Pickups aren't so close to the strings as to cause it, but as an experiment, I just lowered the bridge pickup a bit and retuned. I'll let it sit until tomorrow morning and check it when I get home from werk. There's just the slightest amount of relief visible when sighting down the neck, as well (where I keep all my others).