It's at the Echoplex, they'll have something like 10 - 50 tickets at the door. It's not like, Wiltern policy where I don't think I've ever seen someone turned down, but if you get there around 7:30 you should get in. If you drop by Origami Vinyl next to The Echo (the actual Echo, not Echoplex, it's maybe a block away) they sell tickets as well, but you have to go during the day and I'm not sure they do day of sales. Should call before you pop in but it would save a lot of grief for you if they do.