On the Ultimate Metal Forum I read about Bloodbath's "Nightmares Made Flesh": The sound was created using a BOSS HM-2 into a Marshall DSL50 50W head and a 4X12" Marshall cabinet. Jens miked it with a bunch of different mikes. SM57, Royer ribbon and AKG 414, might have been a MD421 there too, or a U87..don´t remember. he blended all those onto one track and tracked that.
And about Bloodbath's "Resurrection Through Carnage": I used a HM-2 into a Digitech GNX2 preamp. I used the Marshall-amp and Speakeremulation. Later on I used the Free Filter plug-in to "rip" the guitartone EQ from Left Hand Path (using the Intro from "Drowned") and applied that to my own "try". It turned out really broken and like a chainsaw ear fuck!!! Just the way I wanted it!!
It's basically explained in this video: https://www.youtube.com/watch?v=b-1vcuKcXeI (but the Boss HM-2 pedal is not among the ones we can choose
)