I think
 

we hear what we want to hear, though I would never use one I guess they help bring back guitars to some degree of playable instrument. as for martin repair folks using them well thats a first for me all the ones I know replace the top but I guess if a customer asks for that to be done why not right but I am fairly sure that they are suppose to stay in the guitar forever once placed in ( the wood would go back to the last position it was in )thats all I have to say

Could you describe your adjustment process? JLD says to:

"Once the soundpost contacts the tailblock, give the adjustment screw another twist or two and you're finished."

Stewmac's instructions on final adjustment:

"No lateral play in rod, but still can be rotated between thumb and forefinger."

I followed Stewmac's instructions and lost significant volume, but I was concerned about overtightening using the maker's instruction - how much is "another twist or two"? How much is a "twist"? A complete turn? Half-turn?

The maker also says don't be afraid to experiment with adjustments, as it can make a big difference - I've found that to be true.

So, what is your process to final-adjust the JLD?

Once the belly has been removed from the guitar by the BD, and proper humidity maintained, why can't the BD be removed ? I'm not familiar with how it is mounted, but changing that to facilitate removal would be a great plus.

Ed

How much is a twist? About 90 degrees from the start i.e about a quarter turn...according to my wrist :D

What repairman replaces a top because it has a belly?

JLD Research Bridge Doctor
 

Hi all,
I'm coming late to this discussion but I wanted to add my experience to the discussion. I just installed a JLD Bridge Doctor screw mount version into my 1970's vintage Penco A14M (made by Ibanez I've learned). Over the years it has bellied pretty badly causing the intonation to be off and the action to rise.

It's not worth a lot except to me for sentimental reasons (gift from my finance now my wife of 45 years). :up:

I decided to try the JLD Bridge Doctor because it was inexpensive and I had nothing to loose if it didn't work the guitar was doomed to become wall art. Well it worked very well for my situation, the top bulge and tilted bridge are much improved and the intonation is also nearly perfect now. I cannot verify any of their claims of improved tonality or volume, but I like the way it plays now. Well worth the money and the afternoon I spent installing it.
Cheers,
John

JLD Bridge Dr. Adjustment
 

:cool:
You just go by your ear and it's just that simple . Start with the minimal tightness and go from there . It's time consuming but then again , you are there because of liking a guitar anyway .

EZ :

HR

The only time I ever used one it did indeed do what it was intended to do and it worked right away. The bridge rotation that caused the bellying was immediately reversed, the action went back down to normal and the top was nice and flat. There was just tone problem though, the guitars tone was completely ruined.

In the end my opinion of the Bridge Doctor is that it works as intended but it is going to change the tone of the guitar. Some say it's for the better, some say it has changed but who cares, some say they notice no difference. My guess is that the change for the better or no difference are on cheap laminate guitars and that tone for worse happens on well built responsive solid wood guitars. So it depends. IT certainly is a worthwhile and viable fix on cheap guitars but on nicer guitars there are ways to repair excessive bellying.

I used to have a ‘67 Gibson B-25-12 with the big wooden bridge. When I acquired the guitar the bridge had pulled up due to string tension I guess and the action was way high. I had the bridge re-glued and then installed the Bridge Doctor. I was able to immediately lower the action and flatten the top. The sound was greatly improved as well. I left the Bridge Doctor installed and never had any more problems.

That's what I did. Almost 2 yrs now and it still sounds great. Top stayed flat, too. I understand the developer tunes in-place using a device he made out of an old tuner tied to a hex wrench - he can do it through the tuned strings for real-time tuning of the BD.

JLD Bridge Dr
 

:cool:


That's totally hip you were able to figure it out , it's no big deal really as I am sure you realized .

Besides the Bridge Dr. being able to correct belly bulge :

What I have assessed is the Bridge Dr. works like a violin's interior dowel wooden tuning post . The violin
with out one or one not positioned correctly will not yield it's true potential optimum sound , without one
properly placed you had a dud .What matters is the sound and to get the most you can in volume , tone
and play ability .

The are some guitars where the wooden bracing is heavier and from those who have these heavier built
braced guitar and commented that the Bridge Dr. didn't work for them I see maybe the Bridge Dr. has issues
with these type of crafted instruments .

To note is that if installed improperly or not adjusted properly it will sound poorly and in some cases it will
buzz and make a guitar sound muffled and partially muted on the HiHz's .

That's what happened on my first install but after a few adjustments of more tightening and re-positioning the
dowel to true center alignment with the neck it came to life with a booming clear bright tone across the entire
sound spectrum of the guitar .

Also to note that a few comments in the negative come from the owners of ( fill in the blank ) guitars who really
put down the whole concept as a farce or a detriment to the guitar's sound .......

:D - To them I say horse feathers - :D .

EZ :

HR

JLD Bridge Dr
 

:cool:
Considering your post , I thought :

¿ OK so you have a Martin with the first noticeable signs of [ Belly Bulge ] and you do what ? -

• ¿ Complete top removal/replacement ? •

:up:
A JLD will cost you about $55.00 and maybe an hour of your time at most if you are able health
wise and can string a guitar yourself , that's all the needed skill it takes with a JLD Bridge Dr. to
fix a bellied guitar's top .

• :evilgrin: ¿ What is the present cost of a top repair/removal-replacement anyways these days for a Martin ? :evilgrin: •

EZ :

HR

What most skilled repair people do:

1. check the amount of side-to-side curvature of the top behind the bridge to assess if it is excessive
2. check the amount of longitudinal curvature from bridge to butt to assess if it is excessive
3. estimate the amount of bridge rotation to assess if it is excessive.

If I found excessive amounts, I'd check that the bridge is fully glued to the top, that none of the braces are loose or cracked and that the bridge plate is not damaged/cracked. In my experience, those are the primary culprits of excessive deformation of the "belly" in "better" instruments. It would never occur to me to install a Bridge Doctor on an instrument of that quality: it isn't an option. On a garage-sale, abused plywood guitar, maybe.

If you are happy with the Bridge Doctor, great. However, I'm not aware of any reputable repair person who would put one on a "better" instrument as a fix for excessive deformation of the top. Perhaps, it is a limitation of my acquaintances.

The Bridge Doctor is not like a violin sound post.

The violin sound post is held by friction between the top and back plates of a violin snd situated under the treble side of the bridge. It is for both structural and tonal importance.

Structurally, it supports the top plate, acting like a pillar under the bridge. Without it, a violin top would sink in.

Acoustically, the sound post transfers vibrations from the top plate to the back plate. It also effects the vibration of the top plate. A violin without a sound post will sound weak, thin and hollow.

JLD Bridge Dr. Adjustment
 

:D
My point is the difference in tone and volume you experience is definitely similar as the results of what the violin's tone post does .

The transfer of sound off the BD once attached is not noticeable till you add the the added torque off the base of the BD at the hex nut
that then takes the vibrating top's surface . You feel it too as the guitar's tone and volume role out .

So yes you are right and then again the nature of the BD results is similar as I explained to a violin's tone post .

EZ :

HR