On Order. The DM950 USB is an affordable two-channel mixer with two USB audio ports built into the mixer. USB technology allows audio files to be transferred to and from your computer. Mix your computers music files with vinyl, CD, DVD or a microphone. Incorporate MP3, WMA, WAV, and other digital music files in the mix from any USB-equipped PC or Mac. Two USB ports are included so you can take advantage of the multiple sound card feature found in most DJ mixing software.