Signal chain is straightforward, Heil PR 31 -> Onyx Blackjack @55dB gain -> garageband. I only put a bit of plate reverb (a preset on the AU Matrix Reverb on OSX) on the saxophone track in the mix. (As much as I'd like to EQ the sax... er... I have no idea how to use eq :P)
Lovely lovely piece of kit, would definitely recommend it for alto saxophones. I've put in the files on soundcloud as well, and there is a raw version up there as well.
Saxophone Log: October 2011 by Gallen Saxophone Log: October 2011 raw heil pr31 by Gallen