Usually the tape inputs have sounded the best on the Jadis preamps I've owned--probably less wire/bussbar to travel, although there is a cheap relay switch it goes through, which would seem to contradict my observations. On some preamps from Jadis (the JPL and I believe the JPS 2) the CD input has an additional tube in the circuit to supposedly soften the digital glare, that would definitely sound different than the other inputs. Otherwise, I have not noticed differences in my pre--I wonder if some inputs in your pre are more sensitive, and therefore louder at the same volume pot setting?