Well everyone, here's my much-overdue build report on the Gristelizer. I went into this project finding almost no information on exactly what the heck this thing was supposed to sound like. Obviously I had no clue what the terms VCF and VCA actually meant to my ears. Also, there are precious few sound clips/demos of it out there (here's the best one I could find:
http://www.youtube.com/watch?v=37zXCmsGZFk), and there are NO non-experimental sound clips that I could find.
Hopefully this build report will give everyone who is like me a better idea of what is going on with this effect.
Summary: The Gristleizer is a multi-LFO-shape VCF/VCA modulator. For other noobs, VCF is something like Dano's Optochopto (search it!)--it sounds like a wah with an LFO working the treadle. VCA is a tremolo. That's it and that's all.
Controls: VCF/VCA Mode Switch--This chooses between VCA and VCF mode.
Volume--It's the volume control...if you need me to describe it, then go somewhere else

Bias--for VCA, it's basically the intensity of the effect--from weak and pathetic to clipping the opamps. For VCF, it sets the balance between bass and treble at each end of the LFO sweep. Too much bass distorts the opamps harshly. This control is meant to be a trimmer, but I'd say it's absolutely essential to have outside the box.
Depth--Depth is interesting. For VCA, it's pretty standard for a tremolo depth pot. For VCF, however, the less depth you have, the more you get the bottom end of the LFO sweep--meaning if you have depth at 0, it sounds kinda like a fixed wah you can't really adjust. It's a cool easter egg for some applications.
Speed--The slowest speed setting gives you about a 3-second LFO sweep. We're talkin' SLOW. Dime the speed pot and it's almost to fast to perceive without the Depth all the way up. HUGE speed range.
LFO Shape Switch (Ramp Up, Triangle, Ramp Down, Square)--This chooses the different LFO shapes--pretty self-explanatory...the only thing to note here is that you lose some volume on the Triangle setting, since to jank the LFO into a triangle, it loses some of its depth. This is where the bias pot comes in. If you use Triangle, bias it a little hotter. From my experience with the different shapes, the Triangle setting is the one I keep coming back to--it's the most melodic one in both the VCF and VCA modes.
First Impressions: Can easily get wild, clips harshly if you bias it hot, can get LOUD, definitely more lo-fi settings than the average bear...erm...effect.
Build Notes:1. there's an extra pad for the FET on the gm layout--it definitely skips a hole, so check the schematic before you cut the leads. I didn't, and I had to relocate it to the underside of the board. No biggie--I only had one of those

2. Everything on the switch wiring layout on the gm Project PDF is correct...except: you need to jump A1 and B1 together.
3. You need a separate power supply--this beast runs on +/-9v. I used the gm bipolar power supply project, based on R.G.'s schematic. Anything that'll get you +/-9v will do. I used a MAX1044 with good results. I also ignored the input jack power switching portion of the project, which is not needed if you're not using a battery.
4. The gm project uses single opamps--I'm sure this could be improved, but I'm cool with my cheapie 741s

5. Like I mentioned before--move that Bias trimmer to an external pot
6. The other trimmers are to tune the Triangle LFO shape. Mine were pretty good in the middle--this should take minimal adjustment. Keep these as trimmers.
7. Watch your wiring--the LFO can get ticky (even w/ some bleedthrough to the bypassed signal) if you're not careful. The higher you crank the Bias control, the worse it'll get.
8. I added the LFO rate LED mentioned in the comments on the GM site--no ticking problems there--uses a separate NPN transistor to switch an LED based on the LFO. Read it carefully, then draw your schematic from the description. I messed it up the first time...
Pics:
Sound Clip:http://www.zshare.net/audio/65463389045694e7/Chain--Telecaster bridge pickup>Gristleizer>ART tube preamp>Audacity>VST Cab sim
Legend--
Clean Riff
Clean Chord
VCA Ramp Down Riff
VCA Ramp Up Riff
VCA Square Riff
VCA Triangle Riff
VCA Triangle Chord (adjusting from max speed downward)
VCF Ramp Down Riff
VCF Ramp Up Riff
VCF Square Riff
VCF Triangle Riff
VCF Square Chord (adjusting from max speed downward)
Special Thanks:John Lyons did that gorgeous custom powdercoating job for me--BUY HIS ENCLOSURES. DO IT NOW!
Bluesdevil etched me the PCB--thanks a lot man!
gaussmarkov.net provided the project files for the effect and the power supply.
certain_ant--commenter on the gm project page--provided the flashing rate LED solution
Links:gm Gristleizer Project:
http://gaussmarkov.net/wordpress/circuits/gristleizer/gm Bipolar 9v Power Supply Project:
http://gaussmarkov.net/wordpress/circuits/bipolar-9v-power-supply/I think that about covers it. Enjoy!