The Source is a nicely designed, portable device. It's advertised as a monitor controller, but of course is more than that. Its headphone amp and D/A converters are praised by many musicians, as well as audiophiles. It's very easy to set up. I use it on Windows 7, and didn't really have a problem downloading and installing the driver (XMOS), from the Dangerous Music website. Read more
It is even easier to set up on Mac, since you don't need drivers at all (plug and play). The drivers are very reliable. You can play music through it all day, without a single dropout. I would gladly use this if I was a DJ.
I must confess, I had high expectations, regarding the sound. Especially after all the reviews and forums posts I read (Gearslutz, Head-Fi), before deciding to go ahead with the purchase. The truth is that I cannot tell the difference between this and a Komplete Audio 6 interface. Supposedly, it has a really nice headphone amp that can drive even 600ohm headphones, but my AKG k702 (62ohm) sounds the same on this, as it does on KA6, and KA6 is USB powered. I can't hear a difference through the monitors either. Even though the Source uses really nice D/A convertors, mastering quality, as Dangerous claims.
I'm obviously not deaf. The difference in quality is clear when I play music through my laptop's sound card and then switch to the Source or KA6, but people have compared the Source with converters that cost 2 or 3 times as much, and have described its sound as shockingly surprising. I wasn't surprised at all, and I spent quite some time switching between Source and KA6, to determine if there's any audible difference in sound.
About the quality (material wise and built quality), the Source is very nice. I love how smooth and responsive the volume knobs are. It's made in US, and the way it is built, I don't think it will ever fall apart on you. You can tell it is made to be carried around. When I compare it with my KA6 however, which is made in China, KA6 is of higher quality and much more appealing to the eyes.