It takes longer for my amps to come on song than the cartridge, but I warm everything up by playing a couple of sides without any critical listening- i'm sure that's more than enough for the cartridge. I know that the amps (Lamm ML 2) really start to open up at around the 45 minute mark, and continue to improve after that. I don't regard the cartridge warm up as risking any damage to the records if that's the question.
Stylus Warm-up Time
Do you prefer to warm up your stylus before listening i.e. by playing one side (or 2) of an "expendable" LP?
How long is considered acceptable warm up time?
Do you listen immediately or do you wait until the optimisation period is up?
Also what temperature range do you listen at? (My preference is 21-23 degrees C ambient although it doesn't mean I'll stop listening if it goes to 23.5 ;^)