It's possible the rattle was from a loose nut screw, although that wouldn't explain the similar rattle I heard on the Schecter bass. I didn't strip the truss rod, as I said, both nuts turned freely & never bottomed out & I only had to turn them about a half turn to get the neck straight. Not sure how muting the A string will affect a rattle on the B string but after playing the bass for the 3rd time I didn't hear the rattle through my amp that I brought to test it with & felt like it was a non-issue at that point. Even with dead strings it sounded full & punchy through my amp.
