I am looking to buy a Rickenbacker bass and of course they produce 4003 basses now instead of 4001. All of the players I have heard on Rickenbackers played 4001 and their sounds are incredible. But I am wondering what is the main differences between the 4001 and 4003? I mainly need to know the differences in sound but all general differences between them would be good too. I just don't know if I should buy a brand new 4003 or look for a vintage 4001 because they may sound different. But any input on this from experienced Ric players would be greatly appreciated. Thankyou.