I have two basses: a) Fender P MIA 2008, Maple -rosewood, DR sunbeam strings. b) EBMM Stingray 2013, Maple - rosewood, Super slinky strings. Both basses stay in the same rack, same room and I practice every day at the same time. Now, The Fender stays in tune for weeks, regardless of the time I play it or if it just standing in the rack for days, no matter what, when I pick up the bass it is perfectly in tune. That is not happening with the Stingray, every time I pick it up I need to re tune it because is way out of tune, sometimes sharp and other times flat. What makes a bass to stay in tune? The neck. the tunners, the strings, a combination of everything? What I can do to make the stingray to stay in tune like the P?