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.