Well, it's not at full gain at low volumes. The problem is that you can't get that sweet tube saturation you get at high gain settings and high volume. Marshall actually makes a device that allows you to run the volume up so you're getting full power to the tubes (thus complete tube saturation), but cuts the power between the output tubes and the speaker. You get that full, rich distortion at a low volume. When you turn the gain control clear up then play at low volume it sounds more fuzzy that full on crunch.