And the thing sounds phenominal. I picked up a HBE Hema from another TB'er a few weeks ago and I just got my first opportunity to run it through my rig last night at practice with my post-hardcore band. I live in an apartment, and my neighbors probably would not look kindly upon me using my 780 watt 8x10 rig, and my band has been in a bit of a tight spot as for finding a practice space since one of our guitarists (whose house we practiced at) quit.
Anyway, the thing sounds absolutely amazing. I've got the gain sitting around 9:00 or so, and the tone at 11:00, give or take. The "preamp" is at about 3db of boost, and I'm running it after a Symetrix 501 compressor, in the loop of my BOSS NS-2, which then runs into an Aphex Bass Xciter, into my Kustom/Tech21 rig.
I mentioned to my guitarist that I got a new toy, and told him it was a handmade, somewhat obscure bass-specific overdrive. He wanted to hear it A/B'd with my clean sound, so I played a riff clean, then played the same riff with the Hema on. His response was "OH WOW!" Next, I played the riff with the boost kicked in, and he started laughing. He said that he wondered why all of a sudden he couldn't hear himself during the breakdowns.
I told him that most bassists try to cut through the mix, but my goal during really heavy parts is to BE the mix.
This is without a doubt the ballsiest, thickest dirt pedal that I have ever laid my hands on. I really can't recommend it enough.
Just had my first practice with my Hematoma through my rig... 
