Yeah Gar is right! Heck, I use to think the same thing! It is Not the Gear but, the Player, that makes the SOUND!
You see, when you get your Round Wound Bass Strings
they are going to Sound
the way You Play! You'll have to develop your Technique! Then you can try to get as close to JJ's Sound
as you can! Just think of how Fun you will have doing that? :^D