After living solely in the world of acoustic image amplification, I recently purchased a new rig: TC Classic 450 and a Bergantino AE112. Killer stuff! When both the gain and master volume controls are turned up significantly, there is more hiss than I'm used to hearing, especially compared to the acoustic image system. The hiss is only really noticeable when the volume controls are up high which I realize will not often be the case but I just wanted to check would you experts to make sure that nothing is wrong with my TC amplifier. My bass is not plugged in when I am making these comparisons So, increasing the gain control increases the hiss more noticeably than the master control. The hiss increases more noticeably as the dials are turned from 6-10. Obviously I will not be playing with both knobs at 8 or 10, I just wanted to make sure that my amp is not producing more hiss than usual. One other thing: when I turn the gain control, I hear this glitchy sound artifact. Kind of like a quiet crackling/popping electrical sound. Similar to what one hears with a dirty volume or tone pot on a bass, but with a crackling sound. Once I stop moving the knob, this sound is completely gone. Anybody else have this on their classic 450? Any feedback on these two questions would be greatly appreciated. Thanks much!