Pure slow blues lead tone. Fender Vibroverb or Super Reverb cranked loud. The tone comes from the guitar and your fingers — amp does very little.
Signal Chain
Fender Super Reverb→4x10 Jensen→Output
AmpFender Super Reverb
bass
6
gain
7
mids
6
reverb3
treble
5
Cab / IR4x10 Jensen
micSM57
mic positioncenter cap
Notes
SRV tuned down half a step. Use your whole arm for vibrato, not just fingers.