The sound that tends to work for me is my mustang straight into the LMII via a cheapo behringer limiter which is just there to help the overall level as it evens out the levels from my sloppy technique.
At my last gig I took a different bass. I was having trouble getting a sound which sits as well as the mustang as the bass I was using was my Epi T-Bird Pro-V. My mistake was that as I had paid for a two pickup active bass, I felt that I had to make use of everything it offered. Starting with the two pickups 50-50 with the eq flat, I fiddled around trying different things to get it sounding right to no avail until I turned the pickup balance all the way around to the neck pickup 100% + bridge pickup 0%, and the eq flat. As soon as I did that the sound was there. So it seems for my classic old-school flatwound sound, less is not just more, it is everything.