I have a new Christopher 403 3/4 bass and there are two things I want to check out about it: 1. When amplified, the A on the G string and open G string tend to 'run away' and increase in volume 2. Unamplified There is a funny harmonic thing going on when I play the open A string; orchestral pizz particularly brings out a high pitched ring that is the note D. The open A string is a very difficult note to bow cleanly - I tend to get the higher harmonic smudging the note. Jazz pizz in exactly the right place (very close to the end of the fingerboard) can minimize the harmonic. Is there anything I can do myself about these problems or are they better for a luthier to look at?