Denon 4806 AVR Keep it on all day ?

My brother has a similar Denon AVR and it runs warm but not hot.  These are not Class A amplifiers.  Constantly turning a component on and off puts stress on the unit plus the components are always cooling and heating up.  Think about when a light bulb frequently burns out — usually when it’s turned on because that’s when it’s under the most stress.  I’ve have a 20+ year old solid state amp that runs warm and has spent most of that time powered on.  If it were me, I’d say if he knows he’s not going to listen to music for a few days maybe turn it off, otherwise I’d just leave it on. 

My Denon 6300 runs hot so I always turn it off when I am finished.