I have an active bass which features both an XLR jack and an ordinary 1/4" jack. After a bit of research I've found that the XLR would have originally been able to supply phantom power to the preamp, but it's since been been disconnected. I'd like to make it original again and wire it back up... I'm just a bit lost on one of the connections as I've never had a bass with an XLR/phantom power jack before and can't find any diagrams relating to a bass. It's a 3 pin XLR and the bass also takes a 9v battery. One connection on the XLR is still in place and this goes to the positive + wire from the preamp (which also goes to the 9V battery clip). The other pin is ground, so presume I solder that to the ground on the 1/4" jack. The third pin (minus I think?) is the one I'm lost on - I can't see anywhere it came from! I was leaning towards thinking the third wire should be going to output from the volume pot or to the tip on the 1/4" jack, but I'd be guessing and wanted to be sure before testing anything. So any help would be gratefully received! Thank you.