just got this in today and after toying with it for about an hour i felt compelled to share the wealth. I had never really heard of artec, nor seen their effects, but I got this off of ebay for a steal.
First off, this thing absolutely KILLS lowend, so if one is without a blender or some way to get it back i would pass.
that said, this thing is great. white fuzz is a more classic sounding fuzz, reminiscent of a big muff, but a bit fatter when its full on. The black fuzz is a more oscillating fuzz, with similar characteristics to the white, but more gritty.
this thing sounds good with either just white, just black, or both. with all knobs to 11 this gets a really great compressed/gated fuzz that literally sustains forever.
the two fuzzes mix really well, mainly because they sound very similar, the difference is heard most prominantly with pick velocity. black fuzz is a much more gated sound than white. i found a nice compromise with white to about 1:00 and black 3:00, with levels adjusted appropriately.
one thing that i tried that i hated was putting my rat before this, HUGE amount of hiss, but this before the rat with no hiss at all. overall i would give this about 8/10, mainly because i have to dial my lowend back in with my sansamp 50/50 effect loop mix. other than that it sounds fantastic.
i will be sure to post clips when i get a chance.
edit: i also dont like how close the dc jack is to the input, makes a few of my cables unuseable.