Expected life of a MC amp

I have a Rotel RMB-1075 purchased preowned here on Gon about two years ago (120W/Ch continuous, 5 channels). The unit is probably 6 years old and is working perfectly. Original owner took excellent care of it. Just curious how long a unit like this would last and what can I do to maximize its life? I don't do anything to it but use it. I do turn it on via a 12V trigger from my AVR/Pre. What do you all think an expected life of this unit would be? I use it probably 5 times per week for several hours at a clip and do crank up the volume !! Thanks.