I need to add inputs to babyface.  Seems like what's available uses eight even though four channels would do fine for my purposes (tracking drums mainly) Do I  I understand correctly that the adat friendly unit  I  need for these inputs would not utilize the babyface pres or converters?  If true it seems the babyface now becomes just a router to totalmix. 

How does the master clock figure into this?  Can I slave the external unit to babyface clock?  Is that capability or lack of dependent on the specs of the external unit?

I'm thinking of less expensive options here ART tube opto 8, focusrite octopre, etc, but it annoys me that with these units all eight of the adat ins are apparently taken up by one set of converters/preamps.  Probably should get over it, ha.  Guess use one external adat device at a time.

Not too techy, so if you could clear up any any fundamental or not so misconceptions I'd appreciate it.

Thx