You can accomplish the burn-in process either way. I'm too impatient, and don't like to sit through the transformations that take place, to listen for 200 hrs while components burn. I just sample for a while every day. Whatever your signal source, your power amp needn't be turned on to burn-in a pre. To save the hours on my CDP(and it's tubes) I use a tuner, either between stations(white noise kinda), or on a "rap"(yuch!) station for the heavy bass content.
