Ah, grain! Hate grain. For as long as I’ve been serious about audio I have pondered the question of whether it is an artifact that is added as you say; or, caused by the absence of information. By absence of information I mean the incompleteness of the sonic picture; akin to looking very closely at a picture in a news paper and being able to see the dots (pixels) on the page. There is empty space between the dots, so the (sonic) images don’t have enough density as they do in real life. I’ve always thought of this as a “soft grain” because one doesn’t necessarily hear harshness. That was one of the main problems with early digital sound for me, and still is to a lesser degree depending on the recording.
In the case of equipment warming up I think it is, in fact, heard as an artifact that gets added to the sound. In this case, to me it sounds like a sonic artifact that one hears as somewhat disconnected from the musical content; on a different plane from that of the music itself. As the gear warms up the glass on the window into the music gets wiped clean more and more, and more of the music is revealed.
Interesting topic.
In the case of equipment warming up I think it is, in fact, heard as an artifact that gets added to the sound. In this case, to me it sounds like a sonic artifact that one hears as somewhat disconnected from the musical content; on a different plane from that of the music itself. As the gear warms up the glass on the window into the music gets wiped clean more and more, and more of the music is revealed.
Interesting topic.