Triode or Ultralinear mode

When switching between Triode and UltraLinear modes, do any of you speakers POP loudly ?  Mine does and the manufacturer says it's normal and pop-ing is dependent on speakers ! Not sure why... Regardless,  I worry about possible damage to speakers in the long term.

Same is true shutting down the integrated amp...  I first put it on standby mode for 2 minutes, then shut it down... POP !!!  and LOUD !  

To my ears, my SLI-80 siunds better in the UL mode. In the triode mode, it sounds flat and thin, but with better midrange. The speakers are Silverline Sonata-III.

My modified Consonance M800SE Monoblocks seem to sound a bit more dynamic in UL mode. This is with 89 db 2-way speakers. I had been running them in Triode for many years and recently switched. I find the difference depends on source material and usually is minor.

My Aric Audio amp is switchable also and I usually prefer triode.It's not thin sounding at all,the timbre is better but of course won't play as loudly.If I'm in the mood for a big dynamic sound I switch it back.I'm also betting more efficient speakers are needed.
I turn the amp off when switching modes per Aric's instructions.