JTV-69 Bridge Shifted?

[jamiek03]

JTV-69 Korean made 

I purchased the guitar used. After playing it, I noticed the high e string slips of the edge of the neck. I figured it was just me playing sloppy. Then when playing higher up on the neck it was worse, so I looked at the guitar straight on. Up by the nut the strings are well centered on the neck. As you get closer to the bridge the gap between edge of neck on the Low E gets bigger, and the gap between edge of neck and the high e gets smaller. It is to the point of the high e string being right at the edge of the neck. At first, I thought the neck was bad, but then noticed the strings are shifted over the pickup poles as well. So, the 2 bridge mounting points are likely not in the correct location, but shifted causing the strings to be off center the closer the strings get to the bridge. I attached numerous pictures to show the issue.

 

I am not getting anywhere with Line 6 Customer Service on the ticket i opened. Just canned responses and saying they spoke to the tech and a guitar setup will fix the issue. Please advise if anyone has seen this before and how I can possibly resolve?

 

Thanks,

Jamie

[psarkissian]

Bridge isn't capable of shifting, it's position is set by the bridge posts.

Neck alignment issue, it's a set-up thing.

 

BTW,... not a canned response, he consulted me first. I see this all the time with bolt-on

neck guitars like Fenders, Jackson and yes, even Line 6 guitars with bolt-on necks. Had

one on my bench just last week, and another two weeks before that.

 

Guitars go out of adjustment with use over time, these are no exception. And your guitar

is a 2012 build with no service history, so it's been a while. Time for its 50,000 mile check-up.

 

That's straight from me, the guitar tech.

 

 

 

[phil_m]

Looks like the sort of issue being discussed in the article below. Bolt-on necks can become crooked sometimes.

 

https://www.premierguitar.com/articles/21270-guitar-shop-101-how-to-fix-a-misaligned-3-bolt-neck

[jamiek03]

Wow, more answers in 20 minutes than over a week of back and forth with Customer Service. I should have come here in the first place. psarkissian that's all I was looking for was a better explanation of the issue, thank you. As opposed to shipping the guitar all the way to CA, I will go to a local shop to get the setup done.

[psarkissian]

CS told you what I told them, which is what I've said here. They know their stuff, and

I'm across the hall from them, if I'm needed.

 

 

[amsdenj]

I have also noticed on my JTV-69S that the bridge pieces do indeed move (down). Vibrations during playing appear to make the small Allen screws used to raise and lower the bridge to screw in, lowering one side of the bridge saddle. I have to adjust them every couple of weeks.

[amsdenj]

Another useful trick this reminded me of is a way to improve sustain on guitars with bolt on necks. The trick is to slightly loosen the neck mounting screws while the strings are under tension. This will cause the strings to pull the neck tightly into the body cavity, making better contact. Some people think that can improve sustain.

 

[psarkissian]

@amsdenj,...

a) Yes, some margin of play for adjustment purposes. Yes, being for the saddle height adjustment.

The photos above though, are something altogether different in this particular case.

 

b) Useful where the neck-to-body contact is not wood-to-wood, more wood-to-paint. Tight wood-to-wood

contact makes for good sustain. Where resonance gets to be too much, different woods, as in three wood

necks are sometimes used to mediate and level out resonances. It's a similar thing with speaker cabinets.

Tannoy had a DMT series (DMT-8, -10, -12) of speaker with dual concentric drivers for good phase coherency.

To moderate resonance point, they used what they called Differential Materials Technology (hence the DMT). 

 

Similar resonance principles apply when using wood in the world of acoustics.