Cary sli-80 owners

How long do you leave your amp on before critical listening?

I don't have a Cary SLI-80, I have an SLP-05 preamp and CAD-805AE monoblocks. I listen to background music for 60 minutes before I sit down and enjoy myself. 60 minutes is about the time it takes me to fix myself a very nice dinner and get a nice wine out of the cellar anyway :)
I owned and loved a Cary SLI-80 for a while. I found 20 to 30 minutes ideal to light her up.