Question JPX Truss Adj & Relief Problem

[mikeller]

I purchased a new JPX earlier this year. I believe the guitar came with 10's, I switched it to 9.5-44's.

I live in Ohio, where the temperature and climate changes at least 4 times a year and sometimes every other day.

Ever since I have owned that guitar, it seems every few weeks I have to LOOSEN the truss to keep it from buzzing on the open thru 3rd fret areas of the neck. Last week I had to do it again, the truss rod is now almost completely slackened - (actually it was completely slackened, but I then tightened slightly).

Aside from an occasional seasonal tweak, I have never experienced this with my other EBMM guitars.

I have been in contact with the excellent folks at customer service whom have suggested I ship it to them for inspection.

I hate to ship it back for all kinds of reasons - just curious if anyone else has ever experienced this and what the fix was for it?

 

[Spudmurphy]

The joys of owning "raw neck" guitars seems to result in the compromise of having to adjust the truss rod when you have extreme weather conditions.
Switching to a lighter string means that there is less force pulling up from the headstock. Slackening the truss rod would have the same effect too. I'd just back it off further which ties in with the way it came from the factory? See what happens then if needs be send it back to the factory?

However is the JPX a raw neck or a painted neck?

 

[mikeller]

Spud - it is a finished neck. That is part of concern. I almost am afraid it might be trying to back-bow

 

[Spudmurphy]

Hi Mike - yeah I thought it might be a finished neck as I was typing the reply.

I see necks in my mates workshop that are between fulcrun points and they have some weights added to straighten them. Now I wouldn't advocate this with yours, no way.

Normally when you slacken the rod the action seems to lower and you will get more buzzing.
So it could be a case of giving it some forward bow by tightening the rod, but it's unlikely that will have much effect around the 3rd fret. When you see Drew demoing the rod adjustments he doesn't check around the 3rd fret.

I'm only guessing that EB would check all aspects of the set up - saddle height Nut height and also whether the frets are level.

BP hates us diagnosing on the net but I'd just have to put a steel rule on the frets to see if there were any high spots?

So Mike, if I was in your shoes I'd at least try try tightening the rod - keep a scrap of paper and note down the number of holes that rotate on the wheel - that way you can go back to where you are now.

A smidgeon of a turn on the saddle height may help?

OlPlayer had a guitar (not an EB) that I set up - I put a rizla paper under the nut slot and that cured it - so I re did the nut for him.

You don't need me to tell you not to do anything too drastic beyond "normal maintenance" so that your warranty remains ok.

Let us know how you get on?

Edit

I have left my original comments so as not to confuse Mike.
I need to get things straight here - pardon the pun !!

Backbow = tension on the truss rod thereby pulling the neck back
Relief = the string tension pulling the the neck forward.

So to make myself clear the situation is explained thus ...

Back-bow in a guitar neck is a slight curvature in the neck bringing the center of the fretboard closer to the strings. Back-bow, in almost all cases, causes the guitar to play improperly and is almost never desired in a guitar neck. Because back-bow causes the strings to become closer to the frets, back-bow can cause string buzzing and the inability to play on certain frets. Also, intonation may be affected by back-bow. The truss rod will need to be loosened to adjust the back-bow or flatten the neck/fretboard. By loosening the truss rod, you are allowing the neck to assume a more natural shape under the tension from the strings.

Sorry for the confusion

 

[fsmith]

Mike, the original neck on my Petrucci developed a back bow after more than a year. I loosened the truss rod until there was nothing left too. Called customer service, shipped it back and they took care of it. The new neck was even more figured than the original although I know that doesn't apply to the JPX's...

fred

 

[yellowv03]

Hows the nut? Is it low? Seems a lot of JPX's shipped with fairly low to downright low nuts. I think it's due to the jumbo frets. I had to have the nut on mine replaced by CS. Now it is super perfect.

 

[mikeller]

I can't really tell - actually there is some weird look around one side of the nut, never could quite tell what it was. The real issue though is the fact that I have loosened the truss rod all the way and still have almost no relief whatsoever.

 

[DrKev]

Mike - I had a similar issue, I contacted CS about it. PM me if you want to compare notes. But any suspicion of backbow in your guitar neck could indeed require sending the guitar back. Unfortunately one of the things about wood is that, well, it's wood, it won't always do what we want it to!

Seems a lot of JPX's shipped with fairly low to downright low nuts.

Remember, a nut that is too low leaves the open strings unplayable but will not affect anything else. If a problem involves fretted notes, the nut is not the culprit. String height at the nut can can happily go down to the same height it would be with a zero fret and not cause any issues at all. Many of the big name manufacturers install nuts higher than that, often WAY too high, simply because it requires less care and attention in the factory. Playability and intonation suffers. But a lot of people are used to that (unfortunately including many guitar techs) and assume that nuts should be higher than what is actually needed.

Obviously, no manufacturing process is ever 100% perfect. But to suggest that EBMM (who are known for getting it right) regularly get it wrong on just one of their models, on the basis of a small number of known instruments that may have had an issue, just doesn't make any sense.

 

[jvh]

I have to agree with Drkev... I think he hit the nail on the head. I owned one of these guitars and a simple truss rod adjustment fixed it. I sold it to my brother, because the string spacing/width was too much for my liking. However, this was the lowest action guitar I've ever played. It was incredible!!! I think ernie ball actually takes more time in setup on the ball family reserve items probably than the normal production items(just a guess). Remember this is designed for John Petrucci one of the fastest/technical guitar players in the industry. Ernie ball is going above and beyond to set these up as if they were for John Petrucci. Impressive, but thats what you get with a "small" company unlike say a sadocaster. Like DrKev said "no manufacturing process is 100" perfect.", but with that said these are setup in a humidity temperature controlled facility. In my opinion you're looking at what felt to me to be a very thin neck on a guitar that was setup for best playability. Essentially, ernie ball is saving an expensive setup and allowing for just a minor truss rod tweak to fix the problem most of the time if there is a problem. I have to say ernie balls factory setups are probably one of the best in the industry on the bfr models and probably the regulars. I haven't bought a regular ernie ball model in a while only the bfrs. I owned two 25th anniversary and they were killer!!! Best setups I've ever had and I didn't even have to tweak them when they arrived. Anyways, I"m sure they will take care of you, but you may want to try some other tweaks before sending it in. I'm sure they would give you factory nut settings and you could check with feeler gauges to see if it was off.