have you tried the character parameter in the cab section all the way turned up? Turn it all the way up, edit till you get that complex raspy snarl ( I hear it now) then turn the character knob back. You might wanna use headphones to do this. Maybe even dj headphones, no joke.
Thanks for the input. Yes, Cab tweaks can be helpful, been messing with that quite a bit as well. However I'm hearing the opposite terminology. It seems you likely ARE in fact hearing what I'm referring to, but that thing you refer to as rasp is part of what comes out of cranked tube amp. It's a form of harmonic gain content, but it's NOT in the KPA that I've heard so far. What I hear as "rasp" is instead in the KPA. It's a buzzy/scratchy kind of content that is different and sounds fabricated. It's that aspect, and the missing snarl/growl, that makes the KPA sound more fake IMO in comparison to the real thing for these types of tones so far.
Once you start training your ears to recognize these core tone elements, what I've been describing (and a few others as well) will become rather apparent. It isn't about EQ or about compression or about any other excuses floated around. It the core tone structure that simply isn't right. Again, this doesn't prove whether the problem is in the KPA, the existing profiles, or both, but that's what this thread is about, trying to understand how to replicate these types of tones, if even possible.
Sonic