A: There are a couple different ways to accomplish this. For direct-recording/split monitoring, use the direct outs 1-8 on theCR1604-VLZ® to the inputs 1-8 on the ADAT. Outputs from the ADAT should go into the line inputs of channels 9-16. In this scenario, channels 1-8 are for recording, channels 9-16 for tape monitoring.
If you only need to record 1 or 2 tracks at a time connect the sub outs 1-8 to the 8 inputs on your ADAT and assign your channels to the appropriate subgroup. These outputs are double bussed, so whatever you send to sub1 goes to sub outs 1 & 5, sub 2 goes to sub outs 2 & 6, etc. Just arm the track you want to record since the same signal goes to 2 tracks on the ADAT. Patch the direct outputs from your ADAT to mono line inputs 3-11. (Note the handy silk screening on the channels, which corresponds to this setup.)