Low volume out of the RCA output DDJ-SB2 - preamp?

Hello!

I really like the DDJ-SB2, but the RCA outputs seem to be really low.  I am running it to the back of a stero input Focusrite 6i6 for recordings, but it's not very loud.  I have to really scale back my other inputs into the 6i6 and crank the RCA outputs from the front of the SB2.

I am a newbie, but thought that maybe a simple preamp on the RCA jacks between the SB2 and the 6i6 would help lift the level.  I bought this one http://a.co/gMbotFw thinking that would do the trick.  Am I right?  If not, what would I need to boot the output of volume coming out of my SB2?  I tried other software like Djay pro as well as Serato, and it's still the same problem.  I am using a mac, and did change the input and the output to the DDJ-SB2.  There is no volume controller in my mac when I map that way.

Any help or guidance would be really helpful.  Thanks!