Hi All, I'm running an Ashdown ABM 500 EVO III into an SWR Triad. I find the 180Hz EQ control is extremely sensitive, and always have to pull it down some to prevent too much BOOM. I've read here that Ashdown's are bass heavy, and thought I would try another preamp tube. Does anyone have any suggestions for good-sounding tubes that might thin the low-mids out some? The stock Chinese tube is in there now. Thanks.