I have been experiencing an issue with my guitar (67 Guild Starfire II), specifically with the output in the lower register of the A string (open A through fretted D, 5th fret). Its not a string, pickup, amplifier, cabinet or pole height, issue. I seem to recall the nut on my bass having a small crack on it where the A string goes, but Im not near it right now. Either way I am curious as to whether or not the nut can have an impact on how the strings resonate with the body. This issue can be heard acoustically. Its not as noticeable on my guitar (bedroom/practice) amp but its very noticeable on my bass amp. Ultimately I believe the issue is that the vibration of the string doesn't make the body resonate like other positions either on the A string or other strings and therefore the output is not how it should be. I should also mention that I have a repaired headstock using the previously broken parts. However, I know of another person using the same bass with a perfect headstock, different pickups, amp, strings etc and they have experienced this as well. However others have said they've never experienced this before. Thoughts?