frfr has its own idiosyncracies
I would think it would be easiiest to get a good tone going into effects return
How is your input signal/tickling the red?
Maybe post patch on fractal forum
check out the leon todd 5 minute tones on you tube
Rosh Roslin fm3 basics series or the Cooper Carter stuff mentioned above
I would just grab a Friedman or 2204 and let it rip
74 100 watt Marshall canadian superlead with laydown transformers
Friedman Be/hbe modded by friedman off 90s 1959 RI
82 20th anniv 2204 jcm800 all Mullard loaded