Hi Diamond D -
I use my first gen MicroTrack for board feeds and it works well. Just make sure your settings are right (i.e., Low setting, gain turned to zero) and use the 1/4" TRS input, 27db boost off, etc.. Basically, try to take all amplification by the MicroTrack out of the equation and just capture the feed. It works well for me and I have'nt had clipping problems.
I also have an MR-1, and while the sound is great, you might struggle to get it to work without clipping the input stage. The two 1/8" inputs are rated at +6 dBv, which should work for most pro-sumer line outs, but you need a balanced line out to get that level. If you can't get a balanced 1/4" TRS (or XLR) to 1/8" TRS cable, and also have it be a balanced signal from the board, you're going to crush the input stage since its limit for unbalanced signal is much, much lower. I like my MR1, but the input stage is something of a lightweight in its ability to handle a lukewarm (let alone hot) feed. Add to it the internal battery is good for 2hrs MAX, there's probably better solutions out there.
I've also had luck using my Sony D8 to get the SBD feed since the input stage is much beefier, but xfering the take from tape to computer in this digital age is a pain...
Good luck!
Mike