My amplifier gives me a lot of static when I use the clean setting on high volumes. What's going on?

This is on a Marshall Haze 40. Yesterday, I raised the volume on the clean setting up pretty high because I wanted to get some natural distortion.Then today, when I played on the clean setting on a medium volume, my amp sounds broken. I'm sure that none of my tubes are exhausted. Does anyone know what's going on with my amp?