Each of the outputs are balanced, not stereo. That's why you need the TRS. TRS is a balanced 1/4 connector.

I've also used the MXB 1002 and I think it's just about exactly what you're looking for, and you can get one for about $90 bucks. It doesn't have a balanced out put, or an XLR output, but other than that, it will get the job done.