morph question

i was looking to use the morph feature to simply give a rig more volume but found that i could only morph gain not master volume. I don't really want more gain on the morph tone. Any way to leave gain as is and just boost volume?

thanks for the quick response. I just got the unit so learning slowly. Where would I find the rig volume you reference. My stage is at our rehearsal spot but as i recall there is a rig button. Is that where the volume would show up?