I have one and I'm afraid you can't get any grit out of it, it's a fairly warm sounding pre for an SWR but still very clean. I'm in a mood with mine because SWR put in a power amp clipping light that's designed to tell you when the power amp is near clipping, not when it clips. The issue is that the clip light comes on a long time before the power amp actually clips, it's also only just keeping up with two guitars and a loud drummer in a rock band so I'm getting rid of it and getting a GB Shuttle 6.0, which I'm led to believe is a similar clean sounding amp but with the option to add grit with the pre valve.