Same question here, and no, lungho, it's not about the trails parameter/this doesn't solve the issue - when having set feedback to 100%, the signal that was fed is still there after disengaging and engaging the delay switch again. I.e. the signal is not 'clear' of the previous feedback overload signal when switching off and on again. I have found nothing in the settings for this... On the old DL4 this works - you engage the effect, it goes crazy with e.g. The Kills-style machine gun delay >> 100% feedback, and when you switch it off and on again, the feedback is reset. Any ideas?
