What would be your suggestions for an iPhone LOD? -A

Hey guys, I know this may sound odd, but after reciving my PICO portable headphone amp, I'm wondering what the best way is to connect it to my iPhone. I got the USB DAC, so I'm wondering if I can just use a 30-pin to mini usb cable to have the pico convert the audio for me, the way my laptop...

Cant find my post, so if you don't have me already, count me in! -Andrew