Hi Mike,
I've had an AW4416 for two years. The simple fact of the matter is that while the AW line's preamps actually SOUND pretty darned decent, they do not have as much gain as most pres. In fact they have 32dB less gain than the O1V and O2R. This is basically something they did to cut costs. So, on quiet sources you will have to crank the pre nearly all the way up, and on some dynamic and ribbon mics even that won't be enough.
So on a very quiet source, if you can't get enough gain you can use an external pre. On the 4416, sometimes people chain 2 pre's together to up the signal, but I'm not sure how you would do this on the G, because I don't think it has inserts on the two XLR inputs, which the 4416 does.
However, do NOT take Green Hornet's advice. Green, I hate to break it to ya but your "tip" is not actually helping you to get a stronger signal to your recorder, and in fact it's giving you a false picture of what's really going on. I believe you're referring to the "ST" button in the pan/route screen? What that does, is it routes the signal to the STereo bus. Each of those buttons (1-8 and ST) represent a routing bus. You can route say, input 1 to recorder track 5 by selecting the '5' button. However, if you also select "ST" that means the signal is routed to the stereo bus IN ADDITION to bus 5.
You don't want to do that, because when you mix down you will no longer hear the additional signal, and it's not getting recorded to the track anyway - only bus 5 is. So all you're doing is monitoring a low level signal twice while actually recording only once - which means you're hearing it twice as loud but it's not being recorded at twice as hot a level. You will see the level on your master stereo meter get hotter, but the record level on the actual track will not change when you select the ST button.
You can add a bit of gain in the digital realm by raising the fader on the input channel. Also, on the monitor channel, you can turn the dynamics for the track and just boost the output gain, even if you're not actually using any compression or other dynamics on the track. Ideally it would be better to hit the converter at a hotter level in the first place, but since the AW's have comparitively weak pre's you just may not be able to do this. FWIW I have no problems using them on most sources with condenser mics, and even with ribbons or dynamics if the source is loud, like drums or electric guitars.
Also, although lots of people will try to tell you differently, it doesn't kill you if you record the level a bit low (not too extreme, but if it averages around -12 to -6 you should be OK). It leaves you a bit of headroom for processing in the mix that way. Tracks recorded at the hottest possible + lots of compression and EQ on every track = track clipping and a crappy sounding mix. If the levels are a little lower than normal that leaves you some "air" which will help you later. Really.

You can turn a weakness into a strength if you're so inclined.
Also you might want to join the
Yahoo AW User's Group. We discuss the AW4416, 2816 and AW16G, there are lots of experienced folks on there and no one can get away with giving out screwy advice.
Good luck!
--Lee
--------------------------------
What The...?
http://www.what-the.com