i'd run flat, just plug it in, and record. you could use bassrolloff,but i wouldn't. its a trial and error thing, try it, see if you like, it, try it a different way. also, test using the mic in, and line in difference, when i used my MD i found that i had more noise, and it overloaded more often when i went mic in, the mic pre isn't great in those little things.. run the line in, you will probably have more success with that. good luck, hope it works out, +T
matt