So I bought one after hearing some reviews and finding out that it's compatible with Mixxx. However I was a bit disappointed when I connected the RCA output to my RCA input on my computer speakers. The volume was very low and I had to crank it up and the gain to hear anything. Then I read online how you need a preamp to get any usable volume.
But recently I bought an RCA to 1/8" phone jack Y-cable to connect  from the Behringer's RCA outputs to my PC speakers' 1/8" inputs [end edit] and lo and behold the volume was fine! The line level volume was perfect and more importantly usable! No need for any extra equipment. Hope this helps you out!