The cutting out sounds like the response to clipping. Some amps, typically class-D will do that, if they are not designed to tolerate clipping. It can also be protection circuits..... Overheating is usually a longer "outage", 15 sec for a heatsink overtemp, and 30 min if a transformer gets too hot.
I dunno what technology is in that head, I didn't look it up.
As for the smell......
There is smell, and there is smell..... When a newish amp gets warm, there is often a smell of hot varnish as the last of the solvent is cooked out. That isn't a problem.
A real burnt smell has a bit of that sharp smell of a match to it.....
You probably will not get far with warranty service unless the thing actually fails in some way, or the tech finds charred stuff inside.
Yes I USED TO work for Ampeg...but I haven't forgotten everything.