I have an HTC Evo and a FiiO E7 headphone amp that I use to drive my headphones. I am looking for a way to output the audio from my phone to my amp without having to use the 3.5 mm jack. This is because the DAC in the FiiO is much better than the phone's DAC, thereby giving me much better quality sound. When using my computer, the process is very simple: I plug in the amp to the computer using a USB to mini-USB cable and then connect my headphones to the amp. The computer sees the amp as a plug and play external sound card, and it works perfectly. Is there any way to do this with my phone? I know that the iPods and iPhones support this through Apple's proprietary dock connector (I can do this with my iPod). To clarify: I want to use the mini-usb or mini-hdmi cable on my phone to output a digital audio signal to the mini USB jack on my amp/DAC. Also, the amp is battery powered, so as long as I can get the two devices talking, I don't need to worry about power. Thanks in advance for all the replies!