The JDL acoustic guitar bracing system.

[arover2]

Does anyone know how I can find out more about the JDL acoustic guitar bracing system?

I just bought a very good used Breedlove Atlas AD20/SR Plus guitar.

My Breedlove Atlas has the factory installed JDL top brace support system.

Being a used guitar that I bought, it came with no information about the JDL system. The guitar shop owner knew nothing about how it worked.

How does it work, and can it be adjusted to compensate for the top of the guitar bulge or lifting around the bridge area?

And can it be used for proper string heigth adjustment?

I can't seem to find JDL's web site either.

Thanks for any advice.

[Freeman Keller]

Here is a picture of the two types of aftermarket bridge doctors

 

http://www.stewmac.com/shop/Tools/Special_tools_for:_Bridges/1/JLD_Bridge_Doctor/Pictures.html#details

 

JLD used to have a web site with a bunch of information - I may have the URL somewhere at home (I'll look tonight).

 

If you look at the picture you will see a wooden dowel that goes off to the right (of the picture, left of the little diagrams) - that pushes against the end block of the guitar. It is threaded into the assembly that connects to the bottom of the bridgeplate and applies a rotational torque to the b/p and thus the top. The normal tendency is for the strings to pull up on the pins, rotating the lower bout up. The Bridge Doc counteracts this torque.

 

I know that Breedlove builds them into the guitar and have heard that they can use lighter top bracing as a result. My experience was to try to fix a bellied top on my 12 string (it didn't work) but there is no reason why it shouldn't help stabilize the top on your guitar. The only adjustment that I am aware of is turning the rod to apply more or less pressure on the end block - I would do that very gradually and gently (and with the string tension loosened). The intent is really not to change the string (action) height, altho it might have that result. I would adjust it just tight enough that the top is flat and then set your action the normal way. I might have the instructions that came with mine - I'll check and see.

 

I would also contact Breedlove directly and get an owners manual or whatever instructions the offer with their guitars.

[arover2]

Thanks so much for the information. That's a big help.

As for making an adjustment to the Jdl mechanisn inside the guitar, is this correct way to do it... If the top is bellied up, do you turn the adjustment nut clock wise, or counterclockwise looking inside the guitar from the bass side of the guitar?

My top has a swell in the bridge area. The top is not really flat.

So far iIhave contacted three luthiers in my area of Missouri, and they know nothing about Breedlove guitars using this system.

Thank you again for any further information.

....... dkauzlarich@kc.rr.com

[kwakatak]

I just installed one in my 32+ year-old Takamine and got a little overzealous tightening both the mounting screw and the JLD's internal truss. The result was that I actually cracked the bridge all the way through. All 6 peg holes are now joined by a lateral crack that goes all the way down to the spruce below.

 

I'd suggest that if you were going to tighten the internal truss, do it slowly like you would the traditional truss rod on the neck. Turn it 1/8 a turn clockwise and give the guitar some time to adjust between turns.

[knockwood]

http://www.breedloveguitars.com/resources/support/careandfeeding.html

 

Scroll down to:

"Breedlove Steel String Bracing & the JLD

[arover2]

Thanks for the information. I'll follow all the advice here.

[Freeman Keller]

I found the paperwork that came with mine. The URL listed is www.jldguitar.com. (not JDL). There are instructions on line, but the one that came with mine says "Normally we adjust the rod just tight enough so there is no lateral play in the rod, but the rod can be rotated between your thumb and forefinger"

 

If you can't find the site and want a copy of this, PM me a snail mail addy and I'll send it to you.

[arover2]

Thanks Freeman, I found everything on the web sites you gave me. I followed all these directions, plus I printed off all of JLD's information.

This used Breedlove AD20/SR Plus that I bought, I just had a luthier install a quality bone nut and saddle and do a set up.

Who ever owned the guitar before me, took good care of it, but must have used it a lot. It still sounds great, but with a lot of dings, dents and scrapes to it.

I'm so fasinated with this Breedlove model I'm going to buy another brand new one, and placed an order for one with www.music123.com

I still love my HD-28 and my HD-35, but this Breedlove is a keeper. They must really supervise their Korean manufacturijg quality very closley.