You need some kind of interface or soundcard to do that. I believe the motu 896 comes with 8 inputs. What you would want to do is take your outboard gear hook it into the Motu 896 or whatever interface works for you and plug your mics into the outboard gear. So goes like this take a nice preamp hook it into the Motu via line in, adat, spdif, or whatever works for you, then take your interface and hook it into your pc/mac via firewire. I have the digidesign 002r interface for pro tools, it has 16 inputs i think. Adat lightpipe which allows 8 channels thru via lightpipe, 4 mic pres, and 4 line inputs which is what i hook my good outboard pres to. Remember Mic into Outboard Pre into Motu/interface into pc/mac. Sonar will recognize the inputs of the interface you choose. Hope that wasn't too confusing.