Could anyone tell me whats the difference between 60's and 70's Jazz Bass? I remember that someone said thats different pickup location. But whats the different? I could not find it out... Is that the 70's bridge pickup more close to the bridge? And the 70's is 3bolt-on while 60's is 4bolt? 70's knobs are Vol Vol Tone while 60s' are Vol Tone Vol Tone? Also, is there any other difference?