User's of JLD Bridge System (AKA Bridge Doctor)
 

I have a question for those who've used the JLD to pull down a bellying top. I have an old Yamaha that has a bellied behind the bridge. I had the JLD installed to fix this. I'm thinking this is going to take a considerable amount of time to get the belly down as I figure if I try to make it happen too fast I'll slpit the wood some how.

So my question is has anyone successfully used the JLD Bridge System on an old guitar to flatten out the top? How long did it take, what adjustments did you make the the JLD to keep pulling the top down? Any info on what to do or expect would be great.

Thanks

I don't know of any people that have the system in their guitars.
I have read up on the system though and I do think that is can be a good product for guitars like yours.
As I understand it, you will want to be sure that the guitar is properly humified, before attempting to add the pressure of the BD.
Take your time and make small adjustments.

Let us know your results.
I have a Taylor that may be a candidate fore the system.

I have a 40-year-old Martin with a bit of a belly. I put the JLD in there 3 months ago, took string tension off, and left it in the case.

It helps a bit, but it's not a miracle maker. In the pictures that follow, it looks almost unchanged, but there has been some flattening.

Before:
http://i51.tinypic.com/rkt26p.jpg

After 3 months:
http://i54.tinypic.com/28rjzgz.jpg

FWIW, I haven't tightened up the device since the original install.

Another forum member who may chime in with some experience with these is Wade Hampton.
If he doesn't, try sending him a PM.

Someone just recently had ad JLD installed on a Yamaha to be exact. He created a thread with a pleasant story along with it too. I'll try to search for it, but I imagine he chimes in soon.

A difficulty with a laminated top guitar, is that the laminations reset, and it's very hard to convince them to return to the original configuration.

I've installed quite a few JLDs, always for tonal enhancement. Stabilizing the top doesn't hurt, either.

Feel free to PM me, as this usually devolves to a, "they-don't-work-yes-they-do", pile on, here.

I installed one myself 3 months ago in an old Alvarez that was bellying. It hasn't completely reversed it but it has stabilized it and I think it sounds louder and with more sustain than ever. Not sure I would try it on a pricier guitar though.

The he is a she and it is me ;) That was my thread. http://www.acousticguitarforum.com/f...d.php?t=192729

I stand corrected :D

I've found that a bellying bridge is a symptom of a bigger problem so a JLD is a "quick fix." I put one in my 36 year-old Takamine but botched it as I cracked my bridge in the process. It's been holding for a couple of years now but I've been thinking that I may just want to crack the guitar open and fix it the right way on my own. I've done an inspection of the braces and found that one was loose and that the bridge was lifting prior to the JLD installation - neither of which are helping the guitar's tone.

Oh well. At least it was an interesting experience. I took lots of pics - as well as a few older shots of this guitar and others in this album:
http://s727.photobucket.com/albums/ww275/nkwak/Guitars/

Just last week, my friend Jaimes brought his 1972 Yamaha over to have a JLD installed. There was a pronounced belly behind the bridge, and a sunken area between the bridge and sound hole. I knew it was going to set off a chain reaction with the whole setup of the guitar, but Jaimes loves the old lady, and was willing to do whatever it took to get her back to right.

The JLD bridge system, dialed in gradually over a couple days, did a great job straightening out the top distortion. But the action raised up pretty high. Ordinarily, a neck re-set would be called for, because the upper bout had distorted over the years also, and the neck had pulled forward. This was way outside the range of a simple truss rod adjustment. Unfortunately, Yamahas of that era had the necks epoxied in, and you pretty much have to destroy the guitar to get the neck off. My only option to get the string height down was to shave 2mm off the top of the bridge, so I could lower the saddle and still have enough down pressure to drive the top. Fortunately, the bridge was tall enough to do this without compromising its function.

Once I did the bridge mod, as expected, I needed to make a new nut, because the lower action caused the strings to buzz on the first fret.
The guitar sounds awesome, and feels great. But a whole bunch of new buzzes showed up, as a result of all this "chiropractic" treatment. Jaimes is bringing the guitar back for a total refret this weekend. I told him these things would happen, but all he cared about was getting the guitar back in playing condition. I think that new frets, perfectly leveled, crowned, and polished, will add at least another decade to the useful life of the guitar. The restoration work cost far more than the instrument is actually worth, but Jaimes' emotional attachment to the guitar makes it priceless--to him.

Just a heads-up to folks who want to use the JLD bridge doctor or bridge system to fix a distorted top: You may be opening a big can of worms, because one cause will lead to another effect, and you may have to do a totally new setup on the guitar, once the plane of the top is corrected. That could include neck reset, new frets, new nut & saddle, etc. You should look at all those factors before getting the work done, and decide if it's worth it.

Bridge Doctor on LÂG Tramontane T300AE
 

I have a LÂG Tramontane T300AE which developed a belly bulge here in the Philippines where the relative humidity is normally 80-100% everyday.

I humidified the underside of the bridge first by putting a wet rag for an hour, then clamped the guitar between two pieces of wood, tightening slowly to flatten the bulge.

When the bulge flattened, I dried the guitar by putting desiccants inside, covered the sound hole with a sound hole suppressor and wrapped the body in a garbage bag.

After about 2 weeks of sucking the moisture out, I tried stringing the guitar to pitch but to my disappointment the bulge crept in again and increased the string action at the 12th fret from 1.5mm to 2.1mm in 2 days.

I asked a friend to get me a bridge doctor from StewMac and now that it is mounted, my guitar is back, action is steady at 1.6mm.

You can check the pics here.
http://www.flickr.com/photos/edwinme...=%5B%22w%22%5D

I think it was Norman Blake that said "never trust a guitar that doesn't have a belly" and he oughta know. babacaster's experience is the one I had too. I got a little "70's era Alvarez 00 sized, 12 fretter, years ago and it had problems. The belly was so pronounced I decided on the doctor. It worked great and when I moved on to the nut and was working on it one night my daughter fell in love with the guitar and since she had never expressed interest in any guitar prior to that I gifted it to her. It was the greatest little guitar but it was perfect for a beginner heading off to college. It did make it louder and therefore better...but I wouldn't do it on an expensive instrument. Breedlove, I think, incorporates the system into some of their guitars new from the factory.

Generally speaking, if the total rise measured at the ends of the straightedge behind the bridge is 1/2" or less (1/4" on each side) there is no problem to be solved. There are good ways to fix the problem if it does exist. IMO, the Bridge Doctor is not one of them. It adds mass to the bridge and couples the bridge to the tail block, neither of which are particularly good ideas. Still, they seem to sell.

I put it one in a badly bellied 1970s Epiphone all laminate. he JDL is a neat little device. Over several days adjustment it really did a great job of taking the belly out. It held too! But that guitar was bellied enough that the amount of pressure I needed to put on the JDL killed what little tone this beast had (and it was not much to begin with).

I think that if the guitar was less bellied the JDL would have stabilized things without choking off the top. That aside, it help me turn an absolute wall hanger into a playable instrument. I'd have no reservations about trying one again if I was trying to save another guitar for which repair costs exceeded the value of the instrument.

I know this is an old thread, but I recently had a JLD Bridge Doctor installed in my mid 90s D-28, a flood victim years ago. It had a minor belly problem, which is gone now. It is now unmistakeably louder and has more sustain. While that is counterintuative, I do remember violin type soundposts being installed in arch tops years ago, so maybe the Bridge Doctor acts in a similar way. I also had a compensated bone saddle and new tighter bridge pins installed so in fairness maybe some of the improvement in the sound came from that. Intonation is perfect and action is low, the way I like it.

I am now looking for a cheap but quality 12 string with a belly problem to see if it can be returned to useful life in the same way.

Users of the JLD Bridge Doctor
 

I've never used a Bridge Doctor, but I ordered one today, just to find out for myself if it works. Over the years, I have acquired a few vintage guitars, and several have belly bulge close to 1/4" on each side, or are showing some bridge lift, so I'm pretty sure I can use at least one. I ordered the screw type first because I have a Sigma CR-7 classical guitar that has the screw installed but somebody removed the Bridge Doctor. I might order the brass type at some point, if necessary.

Glen

JLD Bridge System
 

Rather than install the JLD and tighten to try and lower the top, what I did was place a damp cloth inside the guitar while placing a number of heavy books on the top for several days (3 to 5 days for softer cedar, 5 to 10 for harder spruce). This alleviated having the JLD system strain when installing (or worst yet break the rod that is suppose to be able to turn by hand by trying to lower the belly).

Important lessons learned, never put wet stuff in guitar without ensuring it rests on something like plastic so as not to wet the wood, as I developed mold quickly. Not that big a deal as it dried but mold is not desirable on anything. This preworking the top flat worked beautifully on my cedar top 12 string, the action and sound is superb, unbelievable. Even Martin uses the JLD to flatten bellies coming back for repair and one manufacturer puts them in right from new.

Another very important lesson learned, place wood underneath the bottom edges on the back as the underside is rounded, I almost flattened mine. Luckily mine was damp enough to push out albeit not as rounded or aesthetic as before it worked well as it hummed up a storm when I then tried to blow dry the moisture, even though I do not recommended this as heat and damp can unglue joints but I was in a nothing to lose situation here and took a desperate risk.

Anyways, this top was cedar top which is soft, and is much easier than the laminate spruce top I am working on now. Here, I used a wet sponge on top of a plastic lid on the inside so it would not touch the wood, and I always did use another plastic top to cover the hole and keep the moisture in, just like the youtube video shows one guy in how he fixed a warped belly. Add a JLD bridge system support after flattening and it won't warp / belly up again, JLD keeps it in place. They should put them in all guitars.

I used books to assist the process again with this spruce top (laminate) but it took much longer to flatten than cedar (twice as long) I now await the delivery of the next JLD bridge system. The books and moisture did work great though. You might want to gradually increase the weight each day, I even had the books and a tool chest resting on top by the 3rd day =)

I found the JLD incredible, works great, the action and tone was remarkably improved to make the guitar a joy to play for hours. I trust it will do just as well on my harder spruce top too. The saddle may have to be raised if you constantly lowered it as the belly rose but this is another topic. If you did you know what to do, get a new saddle and file it down until you get the right height, just make sure the neck is straight albeit trussing is rarely needed. File and install until you have it exactly where you want it balancing tone and action. In my case I blew the first saddle with buzzing but for 6 bucks so what, got another and used the blown one as a reference to make a tad wider. No buzzing, and feather light action. Surprisingly not that much sacrifice on tone either. ...anyway

In short, don't try and make the bridge doctor do all the work. Think about it, it takes one heck of a lot of stress to do so. How can you, especially when the rod is suppose to turn by hand so as not to snap. JLD's tension also has nothing to do with tone as long as it makes good contact so don;t worry there. I like it tight, so I can barely turn it with my fingers with good force, as anything more risks breaking it and reordering a new one takes a week and 30 bucks later. So, level the belly first over a week or two, then its a breeze, and JLD will keep it there forever, sounding better than ever, they say like adding 50 years to the sound of the guitar.

Again, I don't see how anyone can unwarp a belly otherwise without snapping the rod under so much stress/tension, perhaps even when gradually tightening a bit at a time over over many weeks or months which renders it inoperable in the meantime. Perhaps if its is damp inside, dunno...but then who wants moisture in there that long.

I removed the sponge from the spruce top a day ago after it flattened and am letting it dry leaving the books on top until the JLD arrives in the rare event she wants to spring back without a JLD which I understand she doesn't really, or at least not for a long time in the event you want to fix without a JLD making sure it is bone dry before restringing ...but why, to save 30 bucks, when you already went so far and can have a better sound with no more bellying again.

The flat heavy weight (books in my case) on top was invaluable. Don't let water touch the wood and remember the back is rounded so elevate those edges before placing lots of heavy books on top to straighten before installing the JLD, leaving the underneath untouched and rounded.

Hope this helps some one and wished I knew this stuff before trying it myself first and learning the hard way. I feel I can fix any bellied top now, making it louder, clearer, with more sustain, and lower action. What is not to love or rave about. It works awesome, just take note not to repeat any of my hard learned by trial errors. Take extra care if its a very expensive instrument, especially when drilling the bridge, TAKE YOUR TIME.

I do not believe that is correct. I know for a fact that none of the Martin Authorized Repairmen who work on my guitars would install one.

Really? How do you know for sure? Did you ask them?

I read that this was the procedure they used to repair bellied tops and that Breedlove also uses them in every guitar they make from new.

Under JLD's web site they specifically illustrate how a "Martin's" volume was also dramatically increased. I can attest to this volume as well as tone, sustenance, and lower action.

Others use it to repair bellied tops that time inevitably creates, and JLD permanently eliminates. Others, yet, use it to for the sound sake and/or action alone. Like I said I am surprised all makers don't use one like Breedlove does.

As for your repair people, I don't know what they do. I am hard pressed to consider how else one might meet this challenge without the guitar bellying again, even a megabuck top repair would be an odd match with something vintage, let alone time inevitably warping again.

I am sure I read it as part of promotional material than some random testimonial but I can't quickly find it now, that martin uses it in their bellied repair problems.

Maybe you are right, maybe your guys tell you there is no fix unless they replace and rebrace the entire top? Dunno... but if you'd rather spend to rebrace when time inevitably bellies it again, all the power to you. Only half of the guitar will be aged too to also make it an even odder result.

It would make sense that this would be the only practical alternative to fixing any bellied guitar let alone enhancing it and wonder how you are so sure they don't when there are several dozen Martin service centers in the US alone and this is suppose to be standard practice with them.

Breedlove uses them in some guitars, not all.

Based on that, I'll respectfully suggest you have little knowledge of vintage guitar maintenance or repair. This is just not how it works.



Never say never I guess, but no one with any connection to Martin will admit to ever using a Bridge Doctor. (I've asked a few people who should know.) Next time I'm at the factory, I'll ask again.

I've discussed it with a few repairmen. Many of the responses break Rule#1, so I'll leave that there.

No competent repairman would suggest replacing or re-bracing a top because there was some belly. The idea that an acoustic guitar showing some belly behind the bridge is always bad and should be "fixed" is completely erroneous. Some belly is normal, and is either built into the guitar or occurs over time. Excessive belly is often due to loose braces or other structural issues which can be repaired without extraordinary measures.

That said, I'm happy you're pleased with the results on your guitar, but they're not for everyone. They change the tone tremendously and in ways that are not pleasing to me, all the while correcting something that hardly needed correction.

Isn't using heated cauls to bend the wood the generally accepted method? Why would anybody stick something permanent inside their guitar?

http://www.strangeguitarworks.com/ac...-belly-repair/

Heated cauls can work, and from the link in your post...

"Now, an acoustic guitar’s top shouldn’t be dead flat (they are arched, typically with a 4.5m – 6m radius), but this one was severely arched. This one was definitely in need of a debelly job."

As noted above, some belly is normal. I believe people often make the mistake of thinking "flattops" should be flat and go to extreme measures to correct a problem which doesn't exist.

pleased? I am ecstatic, hence my passion.

What didn't you like about the tone, sustenance, and volume that so many throw it on for even without a bellied top? I strongly disagree here in that it transformed my seagull 12 string and a Fender AG10 into supernatural instruments in tone, volume, and profoundly low action that can be played for literally hours effortlessly. The sound blew me away. I am surprised. These are not Martins or Tayors but sound exponentially better tp be than the several thousand ones off the rack, waaaay too tinny.

Martins are well built but when new they sound tinny to me, until they age 50 years. This is what the JLD is said to do, add 50 years to the sound. Even Taylor sounds tinny, albeit not as bad as Martin where a 500 buck Seagull sounds exponentially better than a 2,000 buck Taylor or Martin. Now the 4,000 buck bulletproof Martin had the best tone but still couldn't rival the cheaper 500 buck Seagull but throwing a JLD into that baby would make it supernatural i would imagine, and that is exactly what I would do to preserve the guitar while adding volume, tone, and sustenance. Even though its over a 4 grand instrument I would be nervously drilling to add the JLD.

I am curious and love to be enlightened in exactly what sound qualities are not for you to claim that "They change the tone tremendously" when its more volume and sustenance bringing out the tone that can be easily subdued or amplified, even if it didn't need correction prevented bellying forever that time inevitably forces with 200+ lbs string tension.

Guitars are not forever without this system I guess is my argument, let alone the sound and corrective or preventative action distortion. Like I said, I am surprised they are not putting them in all guitars... yet. =)

Even though I strongly disagree, I respect your opinion as you seem very knowledgeable in this area and I am a tad surprised you found the tremendous change the tone undesirable when it is like adding 50 years to the sound of a guitar. This little device blew me away, for many reasons, action first most and sound an equal second. The amplification of the lows, midranges and highs with such sustenance and volume must be heard to be believed I thought. One could play softer too if they wanted less volume with still beyond incredible sound in my view.

I will research to try and find where I read Martin uses them to repair their bellied tops too. Fixed and sounding waaaay better, why wouldn't they. I'd even do it to a top model brand new one although most people might think this was absolutely nuts to do on something of that value.

Proto - I don't think you are, but you sound like a shill for the company.

On most forums that I have been a part of, new members who start out with such strong support for a product or service are not treated very well, nor are they taken seriously.

Btw, rule #1 is be nice. It's in the FAQ.

If this is a shill technique, it would not be particularly effective on me. To ascribe magical powers and "do it all" attributes to any product renders it to the Sunday morning infomercial category. For the Doctor to help return an instrument closer to its original state (along with other repair techniques), isn't that asking enough? As for me, I found that my $$$ hand built guitar had evidence of a Bridge Doctor at one time (along with reglued braces). I was a little bit bummed, but then again, the fix worked and I'm happy for that. I wouldn't have added a Brige Doctor to make the guitar "mo better" though. That's just me, however.

Based on those statements, what you and I hear, or how we perceive it, is so vastly different that we are effectively speaking different languages.

IME they absolutely kill the tone. The words dead and lifeless come to mind. But again, based on your perception of tone noted above, I don't think I can translate in this format. If we were sitting side by side with sample guitars, I might, but maybe not then even.

Example: I was in a shop some years back and played a fairly expensive guitar (about $8,000 or so at the time) and I liked that model, having played several others in the past. It sounded horrible - dead and lifeless. This puzzled me until I looked inside - Bridge Doctor. I already had an unfavorable opinion, which was reinforced by this mini-blind test.

That's a poor argument. Bellying is just one type of body deformation and not the primary driver of neck resets. Even so, that deformation stops after some time. A guitar might need one, two at most, neck resets. Hardly a fatal flaw.

I can't say that some Martin repairman, somewhere, sometime, didn't install one. However, I did confirm that it has never been Martin policy to use these for ANY repair. I asked several people from Martin (Martin employees, not just Authorized Repairmen) and the answers were always "no/never".

Well we do have a different opinion on sound indeed, so maybe we are indeed speaking a different language on tone. What about volume.

I don't know about neck resets but I was talking bellied tops, this system certainly helped me in many ways in also lowering my action.

For another alias with around 100 posts to name call "shill" for having too few posts or calling it a cure all like a Sunday infomercial strikes me as challenged, rude, and low class with nothing to contribute. Hence my reluctance to further assist or try and dispel stories.

To argue further is futile, with everything knocked, so on that note, sorry I couldn't assist in what worked great for me.

I know this is an old post, but when I read it I noticed that most people have not described in detail what the bridge Dr. Was made for.
First off, all acoustic guitars should have some belly. If it is within proper limitations then all's well. The Bridge Dr. is not made for those guitars.
The Bridge Dr. is made for guitars with extreme belly issues. Issues that make the bridge lean forward, throwing off intonation. Bellied so bad that the bridge is coming unglued from the sound board. Or bellied so bad that the action is way too high or maybe low depending on the exact location of the belly.
My mother has an old Ventura flat top guitar. Is was bellied so bad that intonation was way off, also the location of the belly allowed the front edge of the bridge to sink, or lower, while the back edge turned upward, creating a very low action. Tone was terrible. I was thinking about a neck reset because I didn't truly understand what was happening. I read about the bridge Dr. And decided to try it.
It rotated the bridge to the back which helped the action and intonation, and TONE. Sounded like a totally different guitar.
If installed correctly and for the right reason, THEY WORK! If you don't need it don't use it. If you do, make sure it's installed correctly.