Hey. A little over a week ago, I finished tweaking the setup of my MIM Jazz. I'm no pro at that, but I got it a hell of a lot better than it was before without spending my money at the local store. Farely low, but with a little buzzing in the upper frets unless I played obscenely light. It stayed this way for several days. Then I left school for break and came back about a week later, and it was back to its old ways of high action. Is it normal for a neck to shift a lot like this in the course of a week? If it keeps doing this, what should I do- get lighter tension strings? (I was planning on trying out Thomastik-Infield Jazz Rounds at some point anyway).
i'm no expert on this stuff either, but there's a few things I've learned regarding my basses.... sudden changes in weather (seasons) dramatically changes my setups keeping my bass in different rooms has affected them also, one room is a lot hotter or colder than the rest depending on the season here my cheaper basses are affected more than the better ones. my warwick has a wenge neck and that thing don't budge - I have a couple of dan-electro hodada however and I never know what to expect with them. maybe lighter strings will help - I use medium lights and I dont' think they should cause a problem on any bass. are the screws that bolt the neck to the body really tight? maybve your problem is coming from there. lastly - maybe your setups just take a week to settle for whatever unknown reason?
Sudden changes of "friends" can also cause this Maybe someone "restored" it while you were away? Things usually dont change that fast.
I'm with everyone else on the change in the weather thing. The buzz you were getting may require a truss rod adjustment if you can't get rid of it by changing your bridge setup. Unless you know what you're doing with that, it'd be best if you took it to someone who does.