bapu you are correct. I have got that box too. It converts ADAT sync to Midi Time Code and yes you can lock your sequencer so yes you need that box though. That JLCooper box is good because it enables you to sync up a sequencer without using up any actual ADAT tracks for timecode. Notice how fast it starts the sequencer too even before the ADAT tape is up and running.
 
I am not sure but it might only be frame accurate whereas the PCI card I have is sample accurate but even so it should be fine.

Thanks, all.

If you don't use one of the digital input methods mentioned above, the natural variances in any A/D input method (as wmb points out) are likely to cause timing drift or phase issues because you need to do multiple passes.

For what it's worth, Lightpipe (optical digital/Toslink) interfaces can be found today for not too much $. My Focusrite 18i6 (which is "old" today, I know) has one. Supports 8 simultaneous tracks. Cost $299 new - can likely be found for less than that on eBay or CL today since there are newer variants on the market. IIRC, Lightpipe also carries/allows for time sync between  connected devices as well. Although I am not certain about that list bit, it's been quite a few years since I owned an ADAT.
 
I got my Focusrite partly due to the Lightpipe connector and the ability to use an add-on 8-input/Lightpipe output patch bay for mic'ing drums in the future and haven't caught up to that future yet. Still just using 6 analog inputs and the S/PDIF on it as yet.