Advice required on strange intermittent tuning stability issues
Hoping some of you experts might have an idea here..
I have a 2003 7VWH with an Edge Pro and the locking stud mod. It lives on a wall hanger and gets played only occasionally as although I love the smooth neck and fretboard I find tend to pick up my RG570EX more often because I'm just less worried about it and it has a sustainer installed.
Anyway when I first play it I seem to have tuning stability issues with anything more than light vibrato. These can be from both a dive and pull up - especially a large pull up and range from most strings being slightly out (where by dives and small pull ups along with fine tuning get me back to neutral) to one string out by one or even two semi tones.
At first I thought it was one of the pads at the nut - I tried tightening and swapping these around to see it the string most effected followed it, then I thought one of the saddles was catching on the pickguard, or one was loose (seemed most likely with the large pitch drop). I've checked the stud locks which appear tight and tried to get a bit of chapstick on the posts near the knife edges.
The weird thing messing around like this for a while eventually it will appear fixed and I can generally dive to slack and pull up until I expect a string might break only for me to then leave it hanging on the wall from a few weeks and come back to find the same issue.
Is there something (springs maybe?) that can be effected by lack of use? I sometime think I hear I slight creek or crack when doing an extreme pull up but can never be sure where the noise is coming from...