Quote:
Originally Posted by rarisgod  I had heard about adjusting the setup when changing string gauges, but what would occur if I didn't do this? |
On some instruments, nothing happens at all if you change string gauges and don't get an adjustment. Keep in mind that every instrument is different (even two of the same make and model) though, and there are always exceptions to the rules when it comes to basses and guitars.
What
should happen according to physics is this:
Since you are changing to a lighter gauge there will be less tension on the neck, so the neck may lose some relief (upbow). As long as the fretless doesn't start to buzz, you won't have to do anything about this. If it
does start to buzz (and assuming the buzz is from the lack of relief), the truss rod should be loosened slightly to give a tiny bit of relief back to the neck.
Another thing that may happen is the intonation could go slightly sharp (that is, your fretted octaves and higher notes could be slightly sharp compared to your open notes). As you "fret" the strings to the fingerboard in the higher positions, the strings will stretch, causing the note to go slightly sharp. You correct for this by moving your saddles back slightly.
The
reason the bass might go slightly sharp in the upper positions is that the lighter gauge strings will stretch more than the heavier gauge strings (because they are under less tension). Thus, heavier gauge strings will require saddles that are farther forward (towards the neck) than lighter gauge strings. As you are changing to lighter gauge strings, the saddles are probably already set for heavier gauge strings and may be too far forward, making the higher notes slightly sharp. Fortunately, this is a relatively easy adjustment to make.
Also, if you change the gauge of the strings
drastically, you may need to widen or narrow the nut slots to accomodate the different size strings (wrong-size nut slots can cause buzz and tuning issues). Fortunately, an increase or decrease of .005" doesn't usually cause problems at the nut, so in all likelihood, you won't have to worry about this issue.
Note: If you know how to set your intonation, and have experience safely adjusting truss rods, you can do all of these adjustments yourself. If you
don't have experience doing these adjustments,
especially to the truss rod, you should speak to a professional before you try to make adjustments.
And remember, every instrument is different. Sometimes you need adjustments with new strings, sometimes you don't and its your call whether or not you have any adjustments done.
Sorry about the exceedingly long post. Hopefully you find that info useful. Oh, and trust me, changing string gauges is not as scary as this post makes it sound!
Let me know if you have more questions. Enjoy that fretless!
