if you run gain on the mma, you run a higher chance of brickwalling... I've yet to run my mma on any gain (4060's and high spls don'w need much gain)..... Teddy's advice is correct.
however, if I had 4061s, I'd be tempted to run them on 2 (possibly 4) to send a nice hot signal to the recorder. Try it on an opening band that you might not care about. I borrowed mics and a pre from a friend (I had never run it before). When I was running the pre flat, it wasn't giving me as much volume as I had hoped. The lowest gain setting was +6... so I turned that on, and it caused a lot of visual peaks... so I backed off the volume on my R1 a little bit (iow, threw in the ingredients for brickwalling) but it sounded very very good... brought the source much "closer" it seemed.