I'm a bit of a newbie bassist, so I apologize for what will probably be a silly question. Right. I bought a used bass a while ago and used it just fine, though once I got it tuned, the A string gave me some trouble. On the 10th fret of A, it sounds very warbly / buzzy, and somewhat on the 9th and 11th. This is when it's in tune, anyways. The only solution is to keep tuning until it goes away, but by that point, my A and D are identical in sound. Obviously, this is a problem. I've tried adjusting the action, but to no avail. Looking down at the A and D strings, they are very very similar in gauge; so similar in fact that I think they may possibly be mixed up; though D is in perfect tune. I'm stuck in a rut . Anyone able to help? Thanks, Alex. EDIT: hmm, I should mention that I have no idea of the brand of strings; my bass guitar however is a Peavey Milestone 2. And side question; How would I adjust the trussrod (wheel located in base of neck), and what happens when I do ?