DISCLAIMER:
This is NOT my music and 4/5th of the tracks is not me playing - obviously 
It's just for scientific research - otherwise it would be pathetic and a quite a sacrileg and I'm very aware of that, you bet. So please don't take that stunt serious in any way 
But today while browsing through all the vintage Marshalls and vintage 1960 cabs I wondered how close I could get with the Kemper to a given sound of a famous Marshall player.
I choose my favorite Les Paul slinger and Marshall abuser: Paul Kossoff. So I took out the live BBC-Sessions version of "Ride a Pony" and a live version of "Allright Now". "Ride a pony" has Koss' guitar panned hard to one side which gave me the possibility to noodle around at the other side of the stereo spectrum and compare the sounds. Allright Now has Koss panned dead center which makes comparing a bit more difficult but it still works. I imported the tracks in Cubase and recorded myself playing my Les Paul with the Kemper to this luxurious "backing track". So there are two guitars, Kossoff playing his original version and me playing the other guitar.
I cut and edited both songs into pieces because of not violating copyright issues. Unfortunately I can't upload the complete songs and nobody wants to hear me noodling around with Free for a whole song anyway I suppose.
Anyway, here it is and I think I came pretty close and the Kemper blends in nicely with a 40 year old recording:
http://soundcloud.com/rainer-hain/kemper-marshall-test-01
The profile is "A-Plexi 67 Cranked" by And44 (I think from his first pack) and the '68 Superbass from M. Wienstroer (Kemper Rig Pack 1). I used the same cab from And44 for both amps.
And please excuse the sloppy playing. I was learning "Ride a Pony" as I went along (didn't know the song before) and with Allright Now I only know the studio version and Koss is playing very loosely and didn't stick to his studio version of the solo. So I'm kind of chasing his licks while I went along.