Audiogram 6 set-up help

I'm trying to get my Audiogram 6 running through garageband. Seems simple enough, my mac acknowledges the device and switches input/output to USB Audio CODEC when I plug it in. However, the Audiogram fails to respond to my acoustic guitar (w/pickup) or my mic when I've plugged them into either of the first two inputs on the device (I've set gain at minimum, and the levels at 1 o'clock). I can't get the Level 1/2 peak lights to go off, and the master level L/R signals go off only when I turn up the master level volume past 1 o'clock or so, which my manual recommends against. I don't get any audio back from the computer speakers or any indication that garageband is receiving sound.

I'm a complete amateur, so I don't doubt that the solution is something simple that I've missed. I'm just confused. Thanks.