Hi rusmanxx,
I've had an AW16G for almost a year and have never used anything but the built in preamps. If you're using a condenser mic that requires phantom power and you don't have it turned on, that may be your problem. The phantom power switch is located on the rear panel.
Here's a link to some songs we've done on the AW16G:
How's My Driving Music
bass-shy - the AW16G will record 8 tracks at once.
Here's a link to a forum for the AW16G:
The DijonStock AW16G Support Forum. There are a bunch of guys there that are really nice and very knowledgable about the AW16G.
-Phil