Hey guys, I recently found some settings that make the XTC more JCM 800 like. My XTC is a Classic and I have a 4x12 with GB & H30's so your results may vary etc. Blue or Red ch in any mode with gain not higher than about 1-2 o'clock . Bass 0 Mids 0 Treble 1-2:30 o'clock (This is the only setting on the treble that is useful) Pres 2-2:30 o"clock Structure on high (tight) Old mode When the gain is higher than about 1 or 2 O'clock that amp gets much thicker therby losing the stock Marshall quality . If this setting sounds a bit strident, try moving the structure switch to med or low for more bottom increase mids to 9 o"clock. To me these settings give a much hairier tone that is more in your face. If someone has a Classic and an Helios or 20th XTC please comment how the tone from these settings compares to the tone of those amps. In the previous thread I started, the settings yielded a smooth woody fat tone while these settings give you the opposite tone. Hope you guys have fun tweaking.