F-50 sound problem

[Brad Little]

I'm not sure if I've brought this up on this forum or not, so here goes, with apologies if it is redundant. I have a 1976 F-50 Blonde that was always a killer, soundwise, until recently. Around5-6 years ago, the bridge developed a crack, perpendicular to the neck, right through the pin holes. After I got it back from the shop, it didn't have the volume or sustain that it had always had. I didn't notice it right away, or attributed it to strings or something, so never brought it back to the shop that did that work. Since then, I sent it to Vince Pawless in Texas (who's building a classical for me) and he added a ziricote bridge plate, along with some cosmetic work. This improved the sound a little. I took it to a local luthier who does good work, and all he could find is that the truss rod nut had come loose (probably in shipping from Texas). Tightening it improved the sound a little more, but still not up to its previous standard.The sustain is what intrigues me, or lack of it. It is most noticeable on the sixth string, but not when it is played open-that seems to be about right. But when fretted, it dies sooner than it used to.
My suggestion to both the luthiers who have worked on it is that the bridge somehow is not making proper contact with the top since being fixed, but neither think that would be the cause. I suppose I could just say I want it replaced and see what happens. Any input?

Brad Little

 

[12stringer]

One thing to check is the saddle may not have solid contact with the bridge...it could be as simple as a bit of grit or something has gotten under the saddle...or if the saddle was changed in some way on it's bottom, it may not be perfectly flat which is what it needs to be.
The only other thing it could be is maybe a high fret on the E side since the sustain is less when fretted on one string only.
Hope this helps :wink:

 

[capnjuan]

Hi Brad; I agree w/ Randy about the seating of the bridge but acknowledging that it might be good money after bad, I'd see if I could get back what you had before; an as-close-to-original bridge plate underneath for openers. Was the original bridge glued back together or replaced? If it was re-glued but didn't regain it's integrity ... I guess I'd want it back original even if it meant a fresh bridge and plate. Just my $.02. CJ

 

[Brad Little]

>One thing to check is the saddle may not have solid contact with the bridge...it could be as simple as a bit of grit or something has gotten under the saddle...or if the saddle was changed in some way on it's bottom, it may not be perfectly flat which is what it needs to be.
The only other thing it could be is maybe a high fret on the E side since the sustain is less when fretted on one string only.<

When Vince had it he installed an undersaddle pickup, so I'm sure he checked that out. The original bridge plate was so chewed that the strings were pulling up too much to make good contact. The pin holes were also ramped so that it now needs round pins. Also, after the new bridge plate was installed it sounded a little better. The loss of sustain is most noticeable on the sixth string, but not limited to it.
The most frustrating thing is that everyone who hears it tells me how good it sounds!. Maybe my ears are just getting older.

Brad Little

 

[P-E-Z]

Hey don't I know you from somewhere.

 

[chazmo]

Well, that is intriguing, Brad. Are you using a different string thickness or material (PB vs. 80/20...) on #6 than you used to? I assume you would've told us if your lack of sustain was due to buzzing (so I'm assuming it's not). With that assumption, I don't see how neck angle could be relelvant, so I wont' suggest some tweaking of the truss rod. I suppose it might be an interesting experiment to dial back some neck relief and see if the sustain returns; though, I don't see how it would.

Your comment about it sounding OK open (but not fretted,) is just making me question whether the resonance of the guitar was changed by the luthierie that was done. Maybe a bone or a brass pin would do something positive if that's the case...

I'm not sure that open vs. fretted differences could be explained by this, but maybe the ball-end of the #6 string is not "locked" in place making solid contact against the bridge plate. That said, after multiple string changes, I can't imagine you wouldn't have fixed that already. Do you pull up on the string during a change once you start pressing the pin down? That's what I do to get proper contact / lock. And, Randy's point about the break over the saddle and the saddle contact itself are quite reasonable questions.

Sorry... I'm a little worried for you that two luthiers have been unable to make this guitar sing again... Sorry, I wish I knew what else to suggest.

Oh, do check that your tuners are snug and that the adjustment screws are snug too. That's usually a buzz cure, not a sustain cure, but it can't hurt to check.

 

[capnjuan]

The remarks about the high E are reminiscent of nanccinut's issues Discussed Here. Don't know if it adds anything or not. CJ

 

[Brad Little]

Chazmo said >Maybe a bone or a brass pin would do something positive if that's the case<

I put in brass pins shortly after the first problem, still there. I may change strings and put in the ebony pins that were there for years and see what happens. Also might go back to mediums, I tried heavies to see if they made a difference.
Just bid on a D-50, but see that I've been outbid. Realy want to get a dread and a gypsy guitar (I know, not a Guild), then I think I will be able to settle my GAS for a few months.
Brad Little

 

[john_kidder]

Just a thought from the ignorant but interested:

If the bridge was split longitudinally, and then repaired with (I expect?) a hide- or other good glue, then one would expect the repaired piece to have even more than its original strength, in terms of resistance to breakage in both longitudinal and transverse axes, and its stiffness along the longitudinal axis should still have that of the original wood.

But what happens to the transverse stiffness of the new wood-glue-wood laminate? Is it possible that the glue layer might absorb even the tiniest amount of variation in pressure across the bridge when a string is plucked? And if that were the case, wouldn't that compromise the ability of the bridge to transmit vibrations to the top/soundboard?

Mechanical engineers and glue experts can tell me if this is just nonsense, like so much other idle speculation by the ignorant.

 

[Brad Little]

John Kidder said >If the bridge was split longitudinally, and then repaired with (I expect?) a hide- or other good glue, then one would expect the repaired piece to have even more than its original strength, in terms of resistance to breakage in both longitudinal and transverse axes, and its stiffness along the longitudinal axis should still have that of the original wood<

What I'm wondering is if the repair just glued together the top of the bridge, making it cosmetically okay, but leaving the bottom and the connection to the top suspect.
Brad Little

 

[chazmo]

John Kidder said >If the bridge was split longitudinally, and then repaired with (I expect?) a hide- or other good glue, then one would expect the repaired piece to have even more than its original strength, in terms of resistance to breakage in both longitudinal and transverse axes, and its stiffness along the longitudinal axis should still have that of the original wood<

What I'm wondering is if the repair just glued together the top of the bridge, making it cosmetically okay, but leaving the bottom and the connection to the top suspect.
Brad Little

Well, that would certainly be a possibility, Brad. But, I'm not sure it explains why an open string would resonate significantly better than fretted.

 

[West R Lee]

Personally, I think it could be the undersaddle pickup. Regardless of what some say, it just makes sense to me that if you add a thin strip between the saddle and the wood......you most definatelt lose some contact.....and that could be most evident in just one string.

Does the saddle fit perfectly flat in the slot? Can't rock it just a tad one way or the other?

West

 

[Brad Little]

Personally, I think it could be the undersaddle pickup. Regardless of what some say, it just makes sense to me that if you add a thin strip between the saddle and the wood......you most definatelt lose some contact.....and that could be most evident in just one string.

Does the saddle fit perfectly flat in the slot? Can't rock it just a tad one way or the other?

West

Actually sounded better after the pickup was installed. Before the change in sound, the only modification was the repair of the split bridge. All the mods since have made no negative impact, and, in fact, have slightly improved the sound.
Brad

 

[Default]

This probably isn't necessary, but I find it intriguing and fairly non-invasive.
http://www.stewmac.com/shop/Bridges,_ta ... _Mate.html

 

[12stringer]

Personally, I think it could be the undersaddle pickup. Regardless of what some say, it just makes sense to me that if you add a thin strip between the saddle and the wood......you most definatelt lose some contact.....and that could be most evident in just one string.

Does the saddle fit perfectly flat in the slot? Can't rock it just a tad one way or the other?

West

Actually sounded better after the pickup was installed. Before the change in sound, the only modification was the repair of the split bridge. All the mods since have made no negative impact, and, in fact, have slightly improved the sound.
Brad

Ok then, I would check that the ball end of the E string is seated tight against the bridge plate (like Chaz suggested)...if that doesn't fix it then it could be a high fret which will degrade the sound of a fretted string while usually not affecting an open string. or as you suspect, the original bridge repair may have resulted in a gap between part of the bridge and the sound board in which case I would just have a new bridge glued on and you are back to your original suspicion of what the cause is ...By the way is it the High E or Low E that has lost it's oomph when fretted?

 

[Brad Little]

Ok then, I would check that the ball end of the E string is seated tight against the bridge plate ... or as you suspect, the original bridge repair may have resulted in a gap between part of the bridge and the sound board in which case I would just have a new bridge glued on and you are back to your original suspicion of what the cause is ...By the way is it the High E or Low E that has lost it's oomph when fretted?

No, I've seen pictures of the (new) bridge plate and also "live" with an inspection mirror and the ball ends are seated tight. The frets all appear to be right, and I think I said in an earlier post that it's the sixth string, but maybe not.
I'm half inclined to go with a new bridge, then it will at least ease my mind on that score.

Brad

 

[RussD]

After reading through the topic, I agree with you, Brad. The last action before the problem is usually, certainly not always but usually, the cause. If nothing else, you'd have eliminated the major suspect if you have the bridge replaced.
For me, the next question would be "do I trust my luthiers 100%?"

Best of luck with your decision!

 

[Brad Little]

>For me, the next question would be "do I trust my luthiers 100%?"<
Actually, the only one I wasn't sure about was the one who did the gluing of the split bridge!
Brad

 

[taabru45]

Hi Brad, sometimes you see ebony bridges available. Maybe go that way for the sound, as well as making it different from other F 50s, for identification. Good luck, They're great guitars, l have one. Steffan

 

[GardMan]

Brad...
First, a disclaimer... I know next to nothing about design and construction of acoustic guitars.

OTOH, I think the difference you remember must result from changes that were made to the bridge and bridge plate of your guitar. From what I have read in various forums, the mass and stiffness of the bridge and bridge plate can both have a lot to do with the way a guitar sounds... it's tone and sustain... by affecting how the string vibrations are transmitted to the soundboard (top).

One of the things I have heard in reference to differences between the sound of vintage Martins and the newer versions in the 70s that disappointed some people were changes in the size and wood of the bridge plate... from relatively smaller, maple bridge plates in the "vintage" instruments to larger (even called oversize in some cases) rosewood bridge plates in later years.

So, I would think that changing the bridge plate... both in size, and wood, might make a substantial change in how your guitar sounds. Do you know what the original plate was? My Guild dreads are split between what appear to be maple bridge plates (D-35, D-44, and D-55) and what is obviously rosewood (D-25, G-37, and D-46)... My '72 D-35 has a maple bridge plate. My wife's (now sold) '78 D-35 had a larger, rosewood plate. They certainly sounded very different (better bass from the '72)... but there were other differences in construction that might also contribute to the tonal differences (different bracing thicknesses, and extra block between the neck block and first top brace... the '78 was noticeably heavier).

I also have read claims that the difference between a rosewood bridge and an ebony bridge could substantially affect a guitars tone, just because of the difference in mass and stiffness. The post I remember claimed better response from a rosewood bridge.

So… if I was trying to re-create a sound I remembered, I would try and re-create the original bridge plate and bridge, both in size and original type of wood. Unfortunately… not a cheap fix. But, if it brings back the sound you remember, it might be worth it.

Just my $0.02...and I may be totally off-base.
Dave