If you're going to use another pre amp with an interface.
The interface needs a separate line level input to accept line output
from an outboard pre amp.
You don't have that.
27" Imac 2.93 ghz I7 12GB ram OSX 10.6.5,
MacBookPro 2.4 ghz duo 4GB ram,
Mackie Onyx 1640I, Motu Ultralite Mk3,
LA610 Solo, Logic Pro 9.1.6 DAW