Dissonant overtones

[msintros]

I'm posting this here although this isn't really a G&L question I think but rather a guitar question in general.

I have had my F-100 for a little while now and never really noticed this. When I got it, it was fairly buzzy. I paid the guy to set it up but I don't think he did a very good job. It is slightly less buzzy on some of the strings but still pretty buzzy overall. I tried tonight raising the action just a little to see if that helped. It didn't. It buzzes fairly consistently across the fret board, even open strings. I guess this is neither here nor there though, as my question doesn't really relate to the buzz, but I thought it might help to have some background.

Anyways, since the action adjustment didn't help at all, I lowered it back to where I thought it had been. Now playing I notice something fairly weird. It's possible it was always there but I don't think so, at least not to such an extent. The higher strings, especially the E string, now produce a dissonant overtone, as if there is another string at almost the same pitch also vibrating. I have muted the other strings to see if this is a sympathetic vibration on another string and it is not. It is basically multiple tones being produced on a single string. The "beat" frequency changes slightly depending on what fret I'm playing on. The 12th fret is almost perfect, meaning there is little beating, but other frets away from that produce dissonant harmonics that make the notes somewhat unpleasant to listen to.

What the hell is going on here? Is it hitting against a fret somewhere that is causing a natural harmonic? I'm very discouraged right now. I love the overall sound of this guitar and everything about it except the issues it has have been really bumming me out and I'm thinking of trying to sell it because I don't know if I want to pay someone again to do more set-up on it if it's not going to be just like I want it to be.

[Elwood]

Could it be a tremelo spring ringing? ...or a saddle adjustment screw not seated well .
It sorta sounds like a bad string.
Sometimes detailed pics can help suss these mysteries out.

[KenC]

I would start by putting the guitar back to the factory setup. There's a copy of the instruction sheet in the Gallery section under 1980-81 memorabilia. No matter what year your F-100 was built, those instructions would still apply. The only differences might be Allen wrench sizes if you have one of the newer F-100s. A string change at the same time wouldn't be a bad idea, in case a bad string is a factor. One point of caution is to put a spacer under the back of the bridge (if it's not a hardtail) to prevent it from pressing into the finish when the strings are loose.

Going back to the factory spec should eliminate any fret buzz or other issues with the strings hitting the frets. If that setup isn't to your liking, it will still give you a good starting point for any further tweaking.

Ken

[msintros]

Thanks for the suggestions.

This is just a fixed bridge so it's probably not a tremolo spring. It definitely sounds like it's "in the string", meaning I don't think it's a sympathetic vibration from somewhere else. I did look at the saddle to see if it was not seated. It looked like it was sitting up a bit from the bridge, meaning the two small screws that you use to adjust the string height were not completely touching the metal underneath. I think the tension from the neighboring saddle was holding it up. I tried pushing it down a bit with my finger but it wouldn't go all the way down - it's pretty snug. I loosened the E string enough that it came off the saddle and I kinda re-seated it and tuned it back up again. I'm not sure which thing it was, but the sound I was describing seems to have gone away on that string. It still does it a bit on the B string as well but it's not as obnoxious. I had to go to work so I didn't have time to do much more than this.

I'm gonna have another look at it shortly and see if I can get it to go away on the B string as well.

I'll also have a look at the factory set-up instructions and see if I feel comfortable doing that. With all my years playing guitar I've never really gotten into set-up, so I'm not really that experienced in it. I feel comfortable adjusting string height (although of course this debacle has me realizing stuff can apparently go wrong there as well) but I've rarely attempted to adjust a truss rod. I don't really have a philips screwdriver small enough to fit through the holes to adjust the intonation on this guitar either, so I'll have to hunt one of those down.

[Elwood]

Good news, your right...probably not a tremelo spring
There is a saddle lock set screw on the side of the bridge, did you loosen it before making
the saddle adjustments? That could hold the saddles up a tad and let the height adjustment screws
wiggle some.

Another possibility is the saddle edge has a burr, or lost it's edge.
Is this a vintage F-100?

elwood

[KenC]

There is a saddle lock set screw on the side of the bridge, did you loosen it before making
the saddle adjustments? That could hold the saddles up a tad and let the height adjustment screws
wiggle some.

Please make sure you have this set screw backed out a turn or two before you try to raise a saddle or adjust intonation. Otherwise, the saddles will be locked tightly together (Leo originally called this a "Lock Tight Bridge") and you can strip the screw heads.

Ken

[msintros]

Doh! I didn't even notice that set screw. The saddle screws turned without much problem, so I didn't strip them (yet), but if I make future adjustments to the height I'll make sure to look at the set screw.

For factory settings, I couldn't find the page you mention, but I did find this file http://www.glguitars.com/faq/GLmanual.pdf Not sure if this is the one you were referring to or if there is a more up to date one. This one doesn't appear to tell which size wrench to use for various things. As far as I can tell it's 0.050 for the saddle screws, 1/8" for the truss rod, but I'm not sure about the one where the neck bolts on, as I can't see it.

Re: truss rod, I have noticed mine is either backed out all the way or exceptionally easy to turn. My neck still looks very straight without much bow to it. I know you need a little forward bow to avoid buzzing usually. If it really is loosened all the way and spinning freely and the neck still doesn't have much bow, what does this mean?

[Craig]

Doh! I didn't even notice that set screw. The saddle screws turned without much problem, so I didn't strip them (yet), but if I make future adjustments to the height I'll make sure to look at the set screw.

For factory settings, I couldn't find the page you mention, but I did find this file http://www.glguitars.com/faq/GLmanual.pdf Not sure if this is the one you were referring to or if there is a more up to date one. This one doesn't appear to tell which size wrench to use for various things. As far as I can tell it's 0.050 for the saddle screws, 1/8" for the truss rod, but I'm not sure about the one where the neck bolts on, as I can't see it.

Re: truss rod, I have noticed mine is either backed out all the way or exceptionally easy to turn. My neck still looks very straight without much bow to it. I know you need a little forward bow to avoid buzzing usually. If it really is loosened all the way and spinning freely and the neck still doesn't have much bow, what does this mean?

We have two versions of the original G&L Manuals in our Gallery: See Album: Instrument Manuals and Wiring Schematics.
For the various Allen wrenches, see this post in our G&L Knowledgebase: Can you tell me which allen wrenches I need for my G&L?.

Hope this helps.

[msintros]

Thanks! That's very helpful.

I will need some additional stuff if I'm going to do this, I guess. In particular I don't have anything to accurately measure the string height at various positions.

I did find my nice metal ruler today and used it to see how out of alignment my frets are. The neck looks pretty straight if you look down it (with a very slight hump around maybe the 10th or 12th fret). The straight edge reveals that there is a significant dip in fret height when the ruler is placed across frets 1 to 12 (meaning, around the 5th fret has the most space, being the lowest point in the front bow between those two points), whereas the upper part of the fingerboard is fairly level. I am guessing this is the source of most of the string buzz, which is fairly consistent across the whole neck, but worst before around the 12th fret.

I apparently can't give the neck any more front bow using the truss rod as it's as loose as it will go. I'm also not sure I would even want to because more bow I think would just probably be giving more depth to the frets that already have depth to them and not getting rid of the hump. Of course I know very little of set-up, as I've said.

If this hump is indeed the culprit is there any good way to get rid of this? I am guessing that tightening the micro-tilt screw might help a little but it seems pretty tight already and I'm guessing that over-tightening it is not a good idea and will accomplish nothing but stripping out the wood that it is embedded in. Is fret-leveling pretty much the main option for this? Can someone re-shape the neck by clamping it straight and heating it?

I removed the neck just to see if there was anything going on in there. I also noticed some little cracks in the laquer around the neck joint and wanted to make sure it was just the laquer and not actual cracks in the wood, but it looked OK once I had it off. I was also curious to see if there was a serial number or anything in there, which there wasn't, but there was a date of manufacture for both the body and neck (10/20/80 and 10/24/80, respectively), so the guitar is even a couple years older than I thought it might be.

[Elwood]

I removed the neck just to see if there was anything going on in there. I also noticed some little cracks in the laquer around the neck joint and wanted to make sure it was just the laquer and not actual cracks in the wood, but it looked OK once I had it off. I was also curious to see if there was a serial number or anything in there, which there wasn't, but there was a date of manufacture for both the body and neck (10/20/80 and 10/24/80, respectively), so the guitar is even a couple years older than I thought it might be.

That's an early one. Is the serial on the front lip of the bridge plate? (G00xxxx)
The Laquer cracks at the neck pocket corners is typical.

I bet you will eventually get it set-up to the T, it might take some patience and methodical madness,
or finding a guitar tech who isn't satisfied unti things are perfect.

Pictures? l

[msintros]

Yeah, I think I am going to explore different techs in my area. I paid the guy I bought it from $50 to set it up and he really didn't do a very good job.. it maybe buzzes slightly less than when I got it but it's still really buzzy. I could try to learn to do it myself but I don't want to screw it up somehow. I think it probably needs a fret leveling and that's more than I want to get into. Plus, the frets are fairly flat and I don't know if they'd stand a leveling anyways and probably need to be replaced if it is going to sound really good. That's probably gonna cost a few hundred. Part of me wonders if I should just deal with the buzz and put that money into a second G&L (I've caught the fever now But I've looked to see what other sellers are charging for the F-100 and it's quite a lot (all the ones on Ebay currently are over $1200, probably because they're rare colors). I got mine for $450 so I guess even if I put a few hundred into refurbishing it with new frets, it's probably still not a bad price. It was made the same year I was born, so I kinda feel a spiritual connection to it, and I've never heard pickups that I liked the sound of as much as these MFDs.

Here are some pics!

http://imgur.com/a/cRd6L

http://imgur.com/xT4A5H1

http://imgur.com/LMIzN6e

http://imgur.com/RsNoE0W

http://imgur.com/jlkOANo

http://imgur.com/NKgHQFb

http://imgur.com/1XQb9I4

[Elwood]

Sweet deal!
...and that is considered a somewhat rare color (Candy Apple Red).With the original case and a
nice polishing it could bring twice what you paid on a good day.
I hear ya about the flat frets. A good tech will just find the offending 'bumps' and only after getting
the neck as straight as possible with the truss rod. A less than good tech will take off too much off.
If you can find someone with a jig to pretension the neck (equal to the string tension) you'll have
a really nice playing F-100.
Thx for the pics,everything looks pretty good.

[Elwood]

I am guessing that tightening the micro-tilt screw might help a little but it seems pretty tight already and I'm guessing that over-tightening it is not a good idea and will accomplish nothing but stripping out the wood that it is embedded in.

It will feel tight until the neck screws are loosened a bit. (see official set-up page)
I'm guessing you won't have to deal with the micro tilt, but it's there if you need it.
For now back it out as you reseat(see set-up instructions) and tighten the neck screws,
then just snug it up so it makes contact, but not too hard. Otherwise it's adding tension to the neck heel.

[msintros]

Aha, I wasn't sure what color this was considered. I am slightly red-green color-blind and was thinking it might be burgundy. The only real cosmetic blemish is the ding you can see on the bottom left.

Even with the buzz I still enjoy playing it but I can't help but imagine how much it would sing if the notes weren't fretting out somewhere. It still screams better than any guitar I've ever owned!

If the frets were level, I could deal with the flatness. Usually I play guitars with the jumbo frets and I've heard frets with a more distinct peak will sound better than flat ones, but if I found a tech who thought he could level it out without replacing them I'd be happy with that. So I'm gonna look around. There probably aren't a whole lot of people in my area (New Hampshire) but hopefully I can find someone who can work some magic on this thing.

[andy_tchp]

I did find my nice metal ruler today and used it to see how out of alignment my frets are. The neck looks pretty straight if you look down it (with a very slight hump around maybe the 10th or 12th fret). The straight edge reveals that there is a significant dip in fret height when the ruler is placed across frets 1 to 12 (meaning, around the 5th fret has the most space, being the lowest point in the front bow between those two points), whereas the upper part of the fingerboard is fairly level. I am guessing this is the source of most of the string buzz, which is fairly consistent across the whole neck, but worst before around the 12th fret.

I apparently can't give the neck any more front bow using the truss rod as it's as loose as it will go. I'm also not sure I would even want to because more bow I think would just probably be giving more depth to the frets that already have depth to them and not getting rid of the hump. Of course I know very little of set-up, as I've said.

If this hump is indeed the culprit is there any good way to get rid of this?

it depends on your definition of 'significant dip', but it sounds like you need to adjust the truss rod. Tightening it will lessen the relief or 'front bow'. Setup guide specifies .010"-.012" relief, which is not 'significant' (about the thickness of yr skinny 'E' string).

The official setup guide covers all this and the recommended amount of relief. The results I've obtained by simply following this guide to the letter on my pair of G&Ls have been exceptional.

I am guessing that tightening the micro-tilt screw might help a little but it seems pretty tight already and I'm guessing that over-tightening it is not a good idea and will accomplish nothing but stripping out the wood that it is embedded in. Is fret-leveling pretty much the main option for this? Can someone re-shape the neck by clamping it straight and heating it?

No. No. No. None of these options are necessary to take the excessive relief out of the neck. This is exactly what the truss rod is for.

(Chances are the frets are perfectly fine, even if they're a little worn.)

[msintros]

I don't have a good tool for measuring the dip, but in the worst area I'd say it's more like the thickness of the low A string. But again, this is not consistent across the neck. I'd say that there is a slight back bow between frets 10 or 12 to 22 that might be less than the thickness of the high E (in other words, barely perceptible - the metal ruler will just barely be able to be rocked back and forth) whereas between 10 or 12 to 1 there will be a front bow that is more significant, like I said, about a low A string at the "deepest" point (maybe about fret 5).

Not having a lot of experience playing around with the truss rod, if I tighten it, it will probably lessen the front bow on the lower part of the neck but I would expect it will also make the back bow at the upper part of the neck more significant (?)

Thanks for your input ! Been playing for over 20 years now but always shyed away from (and never really felt I had to) doing set-up adjustments beyond intonation, mainly because I've always owned new guitars.

[KenC]

I apparently can't give the neck any more front bow using the truss rod as it's as loose as it will go. I'm also not sure I would even want to because more bow I think would just probably be giving more depth to the frets that already have depth to them and not getting rid of the hump. Of course I know very little of set-up, as I've said.

Just to be clear, you are turning the truss rod nut counterclockwise (as you look down from the tip of the headstock) and it spins freely? If so, I would check to be sure the nut or truss rod are not stripped. You could try turning it clockwise; if it was backed off enough to remove compression on the truss rod, you will begin to feel resistance at some point if neither are stripped.

I hope everything works out. That is a beautiful F-100.

Ken

[msintros]

Thanks Ken! Yeah I did just that, in fact. It was spinning freely but I turned it a bunch of times clockwise and it started to tense up a bit. So I think it was just loosened all the way. I'm surprised there is not more front bow with it like this but it might have to do with the fact that I play in D standard tuning (every string a whole step below standard), so there is less tension than on most guitars.

[john o]

nice looking guitar, try heavier strings!

[andy_tchp]

I'd say that there is a slight back bow between frets 10 or 12 to 22 that might be less than the thickness of the high E (in other words, barely perceptible - the metal ruler will just barely be able to be rocked back and forth)

Hmm. Even one single high fret anywhere in that region will allow a ruler or 'fret rocker' to rock back and forth. The truss rod doesn't have a huge influence on this end of the neck, so I'm not sure that the diagnosis of the neck being backbowed in the high registers (while having an excessive relief down the other end, and the truss rod is completely loose and not even engaged(!)) is accurate just yet.

(I'm also biased as I've never seen or played a 'bad' G&L neck. Every one I've laid hands on has been exceptional! )

Note that relief is measured at the 8th fret:
http://www.glguitars.com/faq/GLmanual.pdf

If you're seeing something like an A string thickness of relief measured at the 5th fret this is in excess of three times the recommended starting point as per the above manual; the truss rod needs tightening. I'm not surprised the guitar is buzzing.

Just to be clear, that is a massive amount of forward bow to the neck, well beyond 'I like a little extra relief beyond what the factory specifies as I dig in really hard with my picking hand'. There is little point in checking for high frets until this is sorted.

Do not take this guitar back to the person you paid previously, as sadly they did nothing that constitutes a 'setup'

[msintros]

Yeah, when I say the upper part of the fretboard is "back bowed" I might be mis-speaking. Basically I just mean that the fret profile over that region of the neck is in the negative direction overall. It might not be that the neck is actually bowed. I can say that it's more than just one fret. The difference is also not that great over that part of the neck. When Is say the ruler rocks, it is just barely doing so. The forward bow strangely doesn't look that exaggerated when I look down the neck (it looks mostly straight with a slight bow) but apparently it's significant. It might be closer to like a G string in thickness, it's hard to say.

The main thing that confuses me is that I would think that a forward bow would, assuming the entire neck was bowed, eliminate buzz rather than cause it. The problem appears to be that the upper part of the fretboard (i.e. closer to the pickups) is higher than the lower part. The fact that it buzzes even above the 12th fret is puzzling to me as well and tells me I don't really understand set-up in general.

But I'll start by following your first basic advice of tightening the truss rod a bit. As I said, it's difficult for me to perform the procedure in the manual because I don't have any thickness gauges. If I had something I knew was of approximately the right thickness for the different points it notes I could probably do it.

I know the guy who owns the shop I bought it from (he's not the one that performed the set-up) so I might take it back to him and ask about it. I hate to be the complaining customer, but I do feel a bit bummed out that I spent $50 on something that didn't really improve the playability much at all.

[msintros]

Ok, I tightened the truss about a quarter turn (or maybe slightly less) and most of the front bow in the lower part of the neck is now gone.

I let it sit a bit and played it. The strings mostly buzz below the 10th or 12th frets, which is where the "hump" starts. Rocking the ruler at various points on the upper part of the neck seems to indicate there is indeed a steady roundness to most of the upper part of the fretboard (i.e. it rocks a little no matter where I place the fulcrum point). Looking down the neck you can definitely see the hump as well. At this point it seems pretty convincing that this is the cause of the remaining buzz.

Not sure how to go about removing this though. I have not attempted to mess with the micro-tilt again. I thought it would be best to let the truss adjustment settle overnight first before I make too many drastic changes.

[KenC]

Ok, I tightened the truss about a quarter turn (or maybe slightly less) and most of the front bow in the lower part of the neck is now gone.

I think you're heading in the right direction. At least you know the truss rod is functioning. As long as the nut is turning is turning smoothly and you aren't being overaggressive, there shouldn't be any danger with further tweaking.

nice looking guitar, try heavier strings!

Excellent point! What string gauges are you using now? Have you changed strings since you brought the guitar home? I scored an '81 L-2000E from a Guitar Center whose tech had declared it unrepairable. The neck had a significant back bow, and the strings fretted out along most of the board. All I had to do was replace the ultralight strings somebody had put on it with a standard set. As soon as the strings were tuned to pitch, the neck returned to a perfect setup. It's been about five years now, and that bass still plays wonderfully without any further tweaking.

Not sure how to go about removing this though. I have not attempted to mess with the micro-tilt again.

I'd talk string gauges first, just to be sure that's not a factor. Hold off on the micro-tilt until the very end, after tweaking saddle height and intonation. I've owned about three dozen G&Ls and a pair of Musicmans with micro-tilts, and have have only needed to touch the micro-tilt on one of them.

I thought it would be best to let the truss adjustment settle overnight first before I make too many drastic changes.

That's not a bad idea. Going slowly will also minimize the chance of getting confused, especially when you get to saddle height, intonation, and possibly micro-tilt. In fact, it might be helpful to start keeping a record of each adjustment you make, and how it effects each part of the fretboard.

Ken

[KenC]

The problem appears to be that the upper part of the fretboard (i.e. closer to the pickups) is higher than the lower part. The fact that it buzzes even above the 12th fret is puzzling to me as well and tells me I don't really understand set-up in general.

Looking at this again, I think it would be good to rule out "ski jump". That's the term for an upward bend in the neck at the last couple of frets, which can happen over time if the micro-tilt is set improperly. Try playing each string down chromatically from the 22nd fret to around the 17th fret. If they fret out on the 22nd fret throughout that area, you might be dealing with ski jump.

As I said, it's difficult for me to perform the procedure in the manual because I don't have any thickness gauges. If I had something I knew was of approximately the right thickness for the different points it notes I could probably do it.

IMO, thickness gauges are not necessary. Part of this comes with experience and learning what your own preferences are, but I just use a red Tortex pick as a thickness gauge. The factory setup spec was 0.3-0.38 mm, and the red Tortex pick is 0.5 mm. I've found that works well for me (I like low action and hit the strings hard).

I know the guy who owns the shop I bought it from (he's not the one that performed the set-up) so I might take it back to him and ask about it. I hate to be the complaining customer, but I do feel a bit bummed out that I spent $50 on something that didn't really improve the playability much at all.

Another thought on the string gauges: did the guitar tech know you would be playing in D and set it up accordingly, or did he set it up in E and you downtuned afterward? That could be a big factor in whether it was a bad setup.

Ken

[msintros]

The buzz starts around the 12th fret on most strings. I don't really hear a perceptible difference (i.e. little to no buzz) between there and the 12th fret, so I don't think it's ski jump, according to your description.

I didn't tell the tech I'd be playing in D, but it did still buzz even tuned to E the way he had it after the set-up. I played it a bit in the store when I picked it up (I was kind of in a rush at the time so I didn't play very long), and it was slightly better so I think I just kinda let it go but after playing it for a few days after I was like "nah, this really is still pretty bad." Stupid me.

I like the Tortex tip, so I'll grab one of those somewhere!