Truss rod movement extremely effecting sound problem

[Emetal]

One of my guitars, American made Jackson Soloist SL2H. Sometimes would sound very dull, no highs, and then sometimes it would all of a sudden become bright and full of highs. After I changed out all of the electronics through out the time I narrowed the problem down to a truss rod:
-If any work with the truss rod was finished with tensioning the rod - the sound will be OK,
-If the work was done in the opposite (loosening) direction - the sound goes dull.
This literally means that if I wanna loosen the rod for any reason, I must loosen a bit more then needed and then finish by tightening. These are not small differences in sound. I am talking about extremely dull and dead sounding practically unusable or being full of shrills rich harmonics bright good sounding. Also any more extreme work with Floyd tremolo will move it toward being a bit dull. Practically anything that influences a tension rod/neck will play role.
A bit of history: I am the first owner, guitar did have one fall to the ground when it was new, hit the floor with the neck and chipped off paint from behind the tuning pegs. (Never again I plaid without strap-locks ever) Has anybody ever heard of such a problem, is there a solution ???

[J M Fahey]

Canīt even imagine any relation between truss rod tension and extremely bright/dull sound.

There must be some loose contact in the electronics/pikup side, a pinched shielded cable, , cracked wire in a pickup,etc.

Something moving in the wiring gets shorted/open, IF related, tryss rod is justb stretching/shortening/bending the guitr, nothing else.

Try bending the arm, arm to body joint, apply pressure on the pickups, pickup guard, pots, jacks, etc.

[Emetal]

It's a neck through. Absolutely EVERYTHING has been changed, pots, pickups, jack, switch.. It is a truss rod / neck problem 100%. Took me years to figure it out, to connect the dots.
Now I can make it dull and make it bright as I wish.
I just wanted to know is there anybody out there who encountered this problem, because I have never seen it before, and I set up guitars for 30 years... Maybe somebody who build them from scratch could have an idea, cracked wood inside the neck? Truss rod channel routed too wide? Or something?

[xtian]

Please tell us, with the guitar NOT plugged into an amp, can you hear a difference in the acoustic sound, when you manipulate the truss rod?

Knowing whether this is an acoustic (mechanical) issue versus an electronic issue will help isolate the problem!

[Emetal]

Please tell us, with the guitar NOT plugged into an amp, can you hear a difference in the acoustic sound, when you manipulate the truss rod?

Knowing whether this is an acoustic (mechanical) issue versus an electronic issue will help isolate the problem!

Yes, I was just going to write this when I saw your question. IT IS audible acoustically ! No need for an amp to hear the difference. It is EASIER with an amp, but not needed.

[Helmholtz]

I typically experience some change in the acoustic sound of electrics when I change the truss rod tension. But it is barely noticeable amplified.
My explanation is that the truss rod tension influences the resonant properties of the neck. And neck resonances absorb energy from the strings at the resonant frequencies.

In your case I would suspect a somewhat loose truss rod and truss rod anchor, allowing the truss to rotate a bit in its channel. So tightening or loosening would change the contact points/area between the truss rod and its channel.

Fixing that problem would involve removal of the fingerboard.

[Emetal]

Fixing that problem would involve removal of the fingerboard.

Looks like I got the bad apple straight from the factory :-(

[Helmholtz]

Looks like I got the bad apple straight from the factory :-(

Ot the internal neck problem was caused by the shock when the guitar fell on the floor.

[The Dude]

........This literally means that if I wanna loosen the rod for any reason, I must loosen a bit more then needed and then finish by tightening......

So, just do that? Seems like the easiest solution to me.

[Emetal]

So, just do that? Seems like the easiest solution to me.

It is, I agree, it's just not always stable for a longer period of time, extreme Floyd use tend to ruin (a little bit) success achieved by a truss rod manipulation. I guess I will just have to live with it, use brighter string, or just sell the damn thing a bit cheaper and get rid of it.

[Emetal]

Ot the internal neck problem was caused by the shock when the guitar fell on the floor.

True, since that happened quite early when guitar was new, I can never be shore. But it did cost only $1200 brand new, guitar case included, at the Guitar Center (back in 2001). I always wondered..

[eschertron]

It is, I agree, it's just not always stable for a longer period of time, extreme Floyd use tend to ruin (a little bit) success achieved by a truss rod manipulation. I guess I will just have to live with it, use brighter string, or just sell the damn thing a bit cheaper and get rid of it.

If yanking the Floyd back and forth affects the action, I'd suspect that the truss rod (anchor, as mentioned above) is loose. A luthier can remove the fretboard and then you'd see. And if you've had this guitar since 2001, a visit to the luthier might be in order regardless.