[quote name='Dad3353' timestamp='1409516989' post='2540473']
No, I was in no way suggesting that a load of less than manufacturers spec is 'safe', only that, whilst remaining above minimum load, any extra heat will not, in the reasonable life of an amp, be a factor of shortening that life.
Do not run any amp at less than makers spec, at the risk of releasing the 'magic smoke'..!
[/quote]
That's what I was referring to, running a 4 ohm amp at 2.6 ohm.
I know we've debated running at max ohms to get max watts before. Good if you're using cabs that's are gonna benefit from it, not so if you're only gaining a couple of db.
Extra heat will most likely shorten the life. More current going through the components speeds up the wear & tear process (just like with anything).