Here's a quick way to verify whether your USB soundcard supports asynchronous transfer mode (or the claim was false advertising or a confused reviewer or confused audiophile reading the review...*cough-160D-cough*) Source is a microsoft usb audio related doc referring to USB implementation...

I am a bit confused, hoping someone can help here. I will start with my requirements, most of my music are on the computer, so DAC is a must. Some of them are lossless, and I have some MP3 as well. I listen to all types of music. I also watch some movies through headphone so that I won’t disturb...