I have an ASUS slider SL101, and I want to know how I can enable USB audio out. Running Android 4.0.3. I broke the headphone port, so I need an alternative. Solutions greatly appreciated.
Depending on your device (does it support USB OTG) and your Kernel (does it support USB audio) you could probably use any USB class compliant USB interface. You also need to use software that can "talk" to the USB audio device.
One that worked for me was the Shure X2u with one XLR input and a stereo output. I used it to record high quality audio; it also plays back all my music when plugged in. The device I'm using does not have a SIM card so I don't know if this also works for phone calls.
Look at this Android Enthusiasts post for more info.
EDIT: at the moment it's quite hard to find out if those things work on a specific device. Manufacturers don't include the necessary data in their specifications. If your kernel does not support USB audio you can try others but most kernel threads on xda developers don't give information on USB audio so trying yourself is the best option.