Thanks so far guys!

I kinda guessed it was going to be a bit to much to ask for really.

I'm not new to the modelling concept, I know about drum samples and stuff and there done on velocity layers mapped to midi notes. I can guess that the Amps are not mic'd up and captured at multi velocity like the drums because the possibilitys and outcomes would be horrible to deal with as a designer of the pod.

I'm trying to work out in my head how its possible they have done this trying to emulate the heads, the cabs I get the idea of because I understand about impulse reverbs and cab impulses so I can see how they can go about modelling cabs (though I read somewhere that Line 6 don't use impulses, but its possibly based around a similar process). Its just the heads that are confusing me! I have a couple of ideas, but they seem far fetched.

I could go to an engineer that knows about this but I kinda wanted something closer to the source for a solid reference quote for my essay if you get me?

But it looks like that is my only option at the moment unless Line6 feel like shedding the tiniest bit of light on the subject lol.

Thanks again guys! Do you know how to contact Line 6 directly? I tried to find a direct email but it kept sending me here.

Tony