Here are three profiles of my Marshall Studio vintage "SV20H" , author "M ROE".
1) High Treble CH with a Jub 212 w Greenbacks- Moderate gain
2) A reversed jumped into Normal channel first then into High ch, with a jub 212 w greenbacks- warm clean tone here.
3) Normal channel only with low gain into a Bogner 412 w T75s.
Al cabs are Zombiecabs IRs
Enjoy!