I read the Rickenbacker manual....I don't know whether to tighten or loosen my truss rods on my 4003 based on their neck description. Can you help me understand whether to tight or loosen rods for a neck that shows concavity as I look down it?

Thanks.

If you see daylight between frets and strings when you push down on the first and last frets simultaneously, then you have relief, concavity, etc., whatever you want to call it. Tighten the truss rods. If you're standing at the peghead end doing the work, you turn your nutdriver clockwise. Do it about a half turn on each, make sure the bass is tuned to pitch, and let it set a day to see if that is enough. If so, great. If not, repeat using quarter turns. If it starts buzzing, you've gone too far and let off a quarter turn.

Thanks...I see about 1/16 - 1/8 daylight.