Do you remember the chassis expanding sounding “click” that equipment had? You’d be listening and about 15-20 minutes in you’d hear “click” and you knew everything was warm. The sound coming out of the speakers never changed. A couple of decades ago in one of the audio magazines there was a little article about a simple relay needing to be added as the technology changed to simulate the warm up click because people missed the comfort feeling of the click. My Rotel amp does the click. I know my system sounds better after a couple of hours…. but I’ll admit it’s because of a different state of mind. Having, over the years, seen people’s listening posts and drinks and other things, I’d say about 98% of the forum notices the same phenomenon.