What kind of blues are you looking for?
Are you looking to play leads or just basic blues riffage?
I find the clean channel with the gain up at least halfway and pulled, treble about 9, bass about 4, mids about 6-7, presence dimed, master about halfway up, eq set on a slight incline from middle line on far left to top line on far right with the 750 dropped one line from the center to give an interesting cleanish lead for blues. Triode, Harmonics, Tweed, Output on 2, Reverb off. I have been using this setting for a couple weeks just screwing around with some bluesy licks. With a little chorus it sounds pretty good. It is not phenomenal but with a Les Paul it sounds ok especially in the neck pickup.