I think the JB is is quiet a bit higher in output. Hotter tone more growl and harmonics galore. Its kinda brite, you my want to use 250k pots with it. Some will say 500k but youll have experement between the too. Good luck in your tone search.
the PAtb-1 is designed after the JB in that it has a singing tone but the difference between the two is the JB has more upper mids and output(not a lot but more) also the PAtb1 has the exclusive 24 pole design for a different attack.
I really love the JB but the PAtb1 hold its own