I agree Blues. I've been thinking the same.
In the Andertons demo, the external clean boost he used on the Plexi, fattened it out just right.
It needs something like that to make it sound closer to the real thing on most preamp settings.
JTM45, YJM plexi, KK800, JTM60, JTM1, JMP1, JCM1, DSL1, JVM1. Laney Lionheart 5w, Laney Ironheart 15 studio.