My Technics a900s ones more

My Technics se-a900s power amp, had a temperature of 60c on the heatsink, I have replaced the fan with a temperature controlled pc fan and got the temperature down to 43c but is it still too hot for a Technics class AA? I am thinking about lifespan since I want it to last for a long time?
 
However, if you demand an average of 10 real watts at a load of nominally 4 static ohms, then the measured temperature of the heat sink is completely correct.
I would like to point out once again that the temperature measurement using the cheap gun infrared gizmos tells you everything other than the actual temperature of the object.
Stick and glue a PT100 on the heat sink!


Good luck,
HBt.