TheWinterSnow
Den Mørke Natt
Mesa Mark series are not SLO-based, AFAIK.
Mesa Marks have been around for waaay longer than the SLO.
The SLO 100 was made from Mike Soldano's mods he used to do on the Mark III, the first true high gain amp, the first cascading stage amp to be exact, allowing users to get most of their gain from the preamp. Later versions of the Mark series picked up a lot of similarities as Randall Smith took some ideas from Mike. Ironicly, Randall Smith started the same way, modding old Fender Princetons.
MVA801 Beat me too it.