the digi mod means you can use it w/o having the usb connected (which you want)
the batt you could put together from radio shack stuff for 20-40 bucks including charger
you would go sbd to either 1/4", XLR or RCA in, set your levels on whatever you used for your a/d and then use an optical cable that terminates in a 1/8" optical end to go into your jb3
Looking at 20 bucks or so for an opti cable.