Just set it to repeat playing full range music through your preamp. The amp can be off and the preamp can even be off. About a week will get you up into the 150 hour range, which is generally enough (not always). White noise and pink noise doesn't seem to work as well as real music. I use lots of bass and highs. I think it's a waste to buy a special burn-in CD, but go ahead if that attracts you.
Dave