Odd tuning issue - strings constantly sharp

Davo737 · #1 08-01-2010, 01:10 PM

I've been having a very odd issue with one instrument that I've never experienced in any other bass. (The bass in question is a '92 Stingray.) It has been increasingly difficult to tune, and is unable to remain in-tune for any significant period of time, even if unplayed. I can tune it, set it down for 3 minutes, and when I pick it back up, it is no longer in-tune. But, here is where things get odd - all 4 strings always go sharp. Every few minutes, I have to tune down. I've tried different strings, re-intonated, made sure everything seemed structurally OK with the tuners and bridge, but can't seem to fix the issue.

I've called Ernie Ball, and the gentleman seemed just as confused as I am. If anyone has any insight as to what would cause this, I would be very appreciative.

DUC1098 · #2 08-01-2010, 01:22 PM

The only way all the strings could go sharp is if the neck is "stretching". It sounds like something weird is going on with your truss rod or possibly some thermal reaction.

Does the bass continue to head sharp or is it a limited increase?

dmusic148 · #3 08-01-2010, 01:32 PM

My basses all go sharp if I play them a while, tune, and then set it down for awhile. I come back to find all 4 strings sharp. Thermal issue- warm strings vs. cold strings. Sound about right? If so, it's normal. That's why I always tune at the END of a set- while the strings are at 'operating temperature.' They are a bit sharp during the first song of the next set but then settle down. Perfectly normal.

62bass · #4 08-01-2010, 04:09 PM

If the strings and bass, particularly the neck get significantly cooler, like when you put it down for a while, the bass will go sharp. That's a very common problem. I've learned to deal with it on gigs. I just don't retune it, because once I do and play a bit the bass will warm up and go flat. I just pick up the bass and run my hand up and down the neck and strings quickly for about 10 seconds or so. That's usually enough to get me plenty close and by halfway through the song it'll be where it should be.

And I never rely on my tuner. I tune one string with the tuner and tune the rest by ear to that string. No matter how good the bass and the strings and the setup, there will always be a compromise that has to be reached. That works if you play gigs a lot. If you're a hobby player you tend to get all worked up about things like that. I've never had anyone complain I was out of tune on any gig or recording session. But I started playing way before electronic tuners were available. A tuning fork was high tech then. You had to use your ears.

mulchor · #5 08-01-2010, 06:19 PM

I'd wanna look at the nut.

Davo737 · #6 08-01-2010, 06:21 PM

DUC1098, it seems to top out at about a half step or so, but doesn't take very long to get there.

Unfortunately, it doesn't just happen after long playing sessions. I can pick it up for the first time that day, tune it up, and set it down immediately without playing it. A few minutes later, all of the strings are sharp.

I sort of breezed over it in the OP, but just tuning it up lately has been quite difficult. No matter how I tune, be it on an open string or a harmonic, the needle jumps around a ton. In addition, I'm always having to re-intonate. It seems as though trying to keep the open note, the 12th fret harmonic, and the fretted note on the 12th fret in sync is a losing battle. When the 12th fret harmonic and fretted note are in tune, the open string is quite flat. When the open string and the harmonic are in tune, the fretted note is sharp. And round and round it goes.

Davo737 · #7 08-01-2010, 06:27 PM

Quote:

Originally Posted by mulchor

I'd wanna look at the nut.

I don't use a particularly heavy gauge, but if the slots are a bit too tight, that would go far in explaining what's going on. The strings do appear to be sitting all the way in the bottom of the slot, though. I would think that if the sides were too tight, the sting wouldn't sit all the way down. I'll throw a lighter gauge sting in there and see if that helps the situation.

Renaissance · #8 08-01-2010, 06:35 PM

Not to be insulting, but have you tried a different tuner?

DUC1098 · #9 08-01-2010, 07:42 PM

Quote:

Originally Posted by Davo737

DUC1098, it seems to top out at about a half step or so, but doesn't take very long to get there.

Unfortunately, it doesn't just happen after long playing sessions. I can pick it up for the first time that day, tune it up, and set it down immediately without playing it. A few minutes later, all of the strings are sharp.

I think a mechanical issue with the truss rod is unlikely. I would expect it to continue to creep up if that was the issue.

Strings binding in the nut could cause it but not sure how consistent the increase would be over all strings. I think the strings/guitar reacting to temperature is probably a good direction to pursue.

Try tuning the guitar on the stand, or in the case, without touching it as much as possible. See if the same thing happens. This should remove heating from your body as a factor.

The suggestion to try a new tuner is worth looking at also. Even just a weak battery could cause the turner to be unreliable. But again not sure how consistent the change would be with a faulty tuner.

JLS · #10 08-01-2010, 07:53 PM

Quote:

Originally Posted by Davo737

DUC1098, it seems to top out at about a half step or so, but doesn't take very long to get there.

Unfortunately, it doesn't just happen after long playing sessions. I can pick it up for the first time that day, tune it up, and set it down immediately without playing it. A few minutes later, all of the strings are sharp.

I sort of breezed over it in the OP, but just tuning it up lately has been quite difficult. No matter how I tune, be it on an open string or a harmonic, the needle jumps around a ton. In addition, I'm always having to re-intonate. It seems as though trying to keep the open note, the 12th fret harmonic, and the fretted note on the 12th fret in sync is a losing battle. When the 12th fret harmonic and fretted note are in tune, the open string is quite flat. When the open string and the harmonic are in tune, the fretted note is sharp. And round and round it goes.

How close is the pickup to the strings? It might be a mag-pull issue.

DUC1098 · #11 08-01-2010, 08:02 PM

Quote:

Originally Posted by Davo737

I sort of breezed over it in the OP, but just tuning it up lately has been quite difficult. No matter how I tune, be it on an open string or a harmonic, the needle jumps around a ton. In addition, I'm always having to re-intonate. It seems as though trying to keep the open note, the 12th fret harmonic, and the fretted note on the 12th fret in sync is a losing battle. When the 12th fret harmonic and fretted note are in tune, the open string is quite flat. When the open string and the harmonic are in tune, the fretted note is sharp. And round and round it goes.

I just reread this after my last post. Double check all your hardware, especially the neck screws, bridge and tailpiece hardware. The distance between the bridge and the nut being wrong would explain the open/12th issue.

Your description seems to point to the distance from nut to bridge being too short. Open to 12th is set because of the frets, but the 12th to bridge distance isn't. If the neck screws have loosed up, that could explain a lot. 12th to bridge would be shorter and a small amount of warming could cause the neck to tighten while held, then cool when put down.

jsh008 · #12 08-01-2010, 08:22 PM

Have you looked to see if the neck or bridge is shimmed with any type of "off the wall" material? Just a thought. If it is a magnetic pull issue, would changing the battery make a difference to the electronics/magnetic field?

9mmMike · #13 08-01-2010, 08:43 PM

Quote:

Originally Posted by Renaissance

Not to be insulting, but have you tried a different tuner?

I was thinking the same thing.

Davo737 · #14 08-02-2010, 07:11 AM

Thanks everyone for the suggestions. I did double check the tuner, and it is working properly for my other basses.

The pickup height was the first thing that the gentleman at Ernie Ball suggested, but after checking the measurements, that seemed OK (I tend to set my pickups fairly low). There aren't any shims in the neck or bridge, and while I've double checked the screws in the tuners and bridge, I haven't checked to see if any of the neck bolts have loosened - I'll do that when I get back tonight.

Davo737 · #15 08-03-2010, 05:39 AM

And the winner is: the nut. I threw a 40-100 set, and the problems went away. Thanks everyone for their help!