Rvpiano, as I mentioned, your cartridge’s suspension is probably relaxing during the first half hour or so of use. However, as tooblue and others have said “a little of this and a little of that” is probably closer to the truth. For example, how is it possible for “the rest of the system is (to be) fully warmed up” if one has not listened to LP’s yet? Whether stand alone or integrated a phono stage needs to warm up as well; especially if it is a tube unit, in my experience. My experience has also been that it is not enough to simply turn electronics on and let them idle for a while. One has to actually play music through the system for it to be “fully warmed up”. In the case of my all tube system, and as silly as it is to try and quantify these things, I would say that it sounds about 75% of the way to reaching “full sonic potential” after about one record side and pretty close to full potential after two record sides. Full potential even later than that.