Cold XA25

The amp seems to "fit" perfect with the amps we built here......simple low watt amps with only one set of output transistors pr. channel. It has a "nice drive"......better than M2X.....and has also low noise. Less than 50 uV according to spec. It could be even lower in a mono block version.....
 
That is 46.1 deg C, which is very close to Nelson's overall rule of thumb standard of 50 deg C after an hour or so. Don't forget that will change based on your room ambient temperature as well.

i.e. You should just about be able to touch the heat sink for 10 seconds or so, before you get uncomfortable.

Enjoy the XA25, you should be very happy with it.