Now thats a problem
Naka-toroidal transformer na sila and yet...
There are actually two camps battling about power amp protection circuits, to protect or not to protect discussion is truly a headache to follow.
An engineer will say "at this day and age of electronics, an active amp output protection is a must", then another one will say "no protection please, protection circuits mess up the amplified signal and are prone to nasty false triggering".
To make matters worse, this is not limited to discrete power amps, even chip amps aka "gainclones" suffer from this never ending discussion. For example, National Semiconductor's Overture series power amps employ SPiKe (Self Peak Instantaneous Temperature (Ke) Protection) which gives design engineers sleepless nights or even nightmares.
Fwiw, most high current pro amps like QSC power amps donot employ output protection circuits as these truly can cause misfires and false triggering.