New MBP, Final cut pro X & mini-DV capture through Thunderbolt or USB

Hi, I have a Macbook Pro (2015 model), Final Cut Pro X and some old Mini-DV tapes that I need to capture. So we purchased a GV-D900 deck, a 4pin to USB cable (since we don't have a firewire slot) and got to work. The problem is the computer doesn't recognize the deck at all, I've tried FCPX, iMovie, Quicktime Pro X, and looking at the system profiler to see if that registered, it doesn't. So I'm thinking about getting the USB to Thunderbolt adapter, but that doesn't seem like the solution either to me.

Has anyone had any success with the new Macbook Pro? Any workarounds or alternate ideas? Desperate to find any kind of solution to this immediately. Please, any ideas would be taken and considered. Thanks in advance!

Dan