My rig is two AT MB4Ks going into a Presonus Audiobox USB then into line in of my DR-07. I found out that the Audiobox functions as a standalone preamp with USB power so I have been using it in this way. Thing is, I hate to lug around the Audiobox if I don't have to. Is the external preamp really necessary for this recorder? I don't need phantom power as the mics run on AA batteries. Is it ok to go two xlr to 3.5mm straight into line in or am I going to run into issues with levels?