Running my non-powered KPA through a Headrush 112, using mostly TJ and MBritt profiles (clean to high gain) + Celestion IR's,
Sounds great with most profiles. I'll sometimes swap the cab with a Celestion IR or tweak the High and Low shift parameters in the cab section and
that usually gets me there pretty quickly.
Question: Why did you get a Headrush if you have a powerhead? As Clselby mentionned, a non-powered FRFR with the KPA amp would work best IMO.