Silly question HD I/O 16x16 digital

[Nightworker]

From the material those interfaces have no mic preamps. If someone wanted to use mic preamps they would connect it through the adat.. which is logical right, but what if you're using liquid saffires 56 for instance on a pc. From a Focusright sales rep I learned that you can connect your second unit into the first liquid saffire 56 adat and then the first unit through fire wire without having to do an aggregate device since this would be on PC. You'd then get access to all preamps, but you wouldn't be able to use the liquid preamps of the second unit. So why would someone need those HD interfaces?

I guess you could connect each liquid saffire into each adat port?

I'm just trying to figure out if you need any preamps with those interfaces and if so, how to best utilize them.