So I've been looking to put a little fur in my signal, and when I say a little, I mean just a little. I was looking for a really mild overdrive pedal when I realized that my Ashdown EVO head (original, not II or III) has a tube built in, presumably for this specific purpose. When I bought the amp I was looking for a clean signal, so I never really thought about it, but when I messed with the grind knob, I have not found a way to get anything I would qualify as actual tube breakup from it. It certainly changes the tone in some way, maybe even making it a little more "grindy", but no overdrive/distortion. And yes, I tried cranking the input and driving the amp as hard as I could, no luck. I popped it open and took a look but the tube was unmarked so I don't know what kind it is. Anyway, I was just trying to find out if this was normal or not and if anyone else has had a similar experience. If I should be getting some kind of distortion (with the grind knob cranked I might add) could it be that I need a new tube? If so, what do you recommend? If not, I'll probably look into something like a VT bass pedal or an English Muff'n (any opinions on those pedals would be nice too) to satisfy my yearn for overdrive. Thanks for your help, I don't have a lot of experience with natural overdrive so I'm kind of stumbling in the dark on this one.