Amp shuts off after certain volume

[Blingbo]

So I write it off to the amp's safety feature, but I want to be sure it really is fine and not some problem to consider. I have a Technics SU-800 stereo amp and if I pump the volume above 1.5 out of 10, the safety turns off and sound stops playing. It's loud enough below that, but I just wanted to see what the speakers' limits are (some cheap "Thunder" floor speakers, 2 or 3-way, around 100W power). The amp has been taken to a engineer by the prev owner in 2015 for general repairs. Now I haven't pumped the volume above 1.5 in a year, because I'm scared of shorting something and there's no point. Reason for this thread is that my dentist is an audiophile and said that an amp cant shut itself off because of weak speakers. Which one of us is right? No rush, its not urgent, thanks!

 

[Lutfij]

Do you have a link to those cheap speakers? The amp you've stated can deliver 50W per speaker which are each rated for 8 Ohm impedance thus my follow up question...what are the specs on your cheap speakers?

 

[Blingbo]

Do you have a link to those cheap speakers? The amp you've stated can deliver 50W per speaker which are each rated for 8 Ohm impedance thus my follow up question...what are the specs on your cheap speakers?

Ah, my bad, forgot about that. 8 Ohm impedance, 89dB sensitivity, 10-100W on power and 20kHz freq

 

[americanaudiophile]

An amp can shut down when it detects clipping distortion caused by its reaching it's power output limit. This can damage tweeters so a protection circuit can be designed to operate quickly.
It can be caused by a bad driver or crossover part in the speaker system or an "almost short" in a speaker wire. If there are wires really close together they will short when the power of the amp goes up enough to jump the gap between the wires.