Framus amps,
Hughes and Kettner Triamp,
Carvin Legacy. Official schematics below.
Framus Amps
here are all the official schematics
Why? I worked for Framus/Warwick some time and in my opinion these amps were really good and on the other hand - different than amps that we already have in Axe.
Cobra
This is an extremely tight modern higain amp, great for low tuned guitars, modern death metal, stuff a'la Fear Factory etc. A bit similar to Engl Savage in response. It has a mid-cut switch, but I would leave this function off - we still have a lot of ways to cut the mids.
Dragon
Thick sound with grainy drive, a lot of gain - works very well for stuff a'la Black Label Society. It has a more classic response than Cobra
Ruby Top
Framus Class A design. Plenty of gain, nice, round sound - this is Vox meets Matchless. Very responsive to volume knob in guitar
Hughes and Kettner Triamp
I own this amp for many years. I would like to see EL34 version modelled (it has a bit more bite in midrange). Channels 3A and 3B are my personal favourites. 3B is something like Recto meets SLO100 but still got it's own flavour. 3A is very responsive, dynamic, demanding and thick sounding.
Official H&K Schematic
Carvin Legacy
This amp has a quite unique voicing - a lot in Marshall direction but still different. Why should it be added? Steve Vai sound - for starters. Again - responsive to playing dynamics and volume knob, huge midrange, works very well for low gain rhythm and cool lead sounds when pushed with overdrive pedal. And again... Steve Vai.
Schematic