Hypex done right and kept cool will have a reasonable life. There are too many components on an NC-252MP (
@boXem 's example), which run hot especially when the entire unit is placed in a poorly ventilated steel case it will overheat.
I can't measure the temps of the 252s I have here because they are all dead. I've pretty much given up trying to repair these things as the information/schematics are not forthcoming from Hypex. You have to ask yourself if you want to buy into that ecosystem*. I sure don't.
* not much "eco" about throwing out entire two channel amplifiers and PSU modules is there?
The ratings are not optional. The operating temperature of the Hypex modules is 65 degrees maximum operating temp.
That doesn't mean the air temperature in your room- that means the long term environment inside the casework. The output filters run very hot at idle as do the SMPS transformers, the primary side switchers, the secondary side and so do the filter caps. The air inside the casework rapidly exceeds the maximum operating temperature. My thread showed plenty of thermal images. I mean seriously, an NC-500 output filter sitting at 167 degrees F (74.9C) doing nothing- just turned on, is ridiculous. How do you think the capacitors sitting alongside will fare long term?
Thermal:
Visible:
The 252mp module overtemperature will trip at just 85 degrees.
Not remotely difficult to get there if you play load music on a hot day with a poorly implemented thermal design. As for squeezing multiple units into a single case with no fans, no actual heatsinks and a mild steel construction like some use, I don't know what to say.
Without forced air cooling
on the heat producing parts, the life of the amplifiers will be measured in single digit years. Is that good enough for you? If it is, you pays your money and you takes your choice.