Hi!
I also play in a band were I only use "loud and clean" I use low output humbuckers and single coils and set my amp like this.
Channel 1, Clean or Fat mode, bold switch on, 90 watts, Gain 3 o´clock, Treble between 12-2 o´clock, Middle between 10-1 o´clock, Bass 11 o´clock, Loop on, Output, 12 o´clock or higher and use the "Full power"/-not Variac.
Now what i´ve found is that when adjusting the channel Master with the Loop on, the Master starts to distort if it goes above "10" o´clock so it´s better(at least with my pickups and settings) to set the Gain high, increase the Output knob above 12 o´clock and even using the Solo feature to increase volume even more cause they seem to come later in the circuit. And of course bear in mind that the Treble can make it breakup if set "too" high!
Take care and good luck!
/regards Jesper