Plug in preamp while amp is on caused very loud pop on speaker.

Long as all the drivers sound right(are functioning properly), you’ll be fine. Large, damaging transients will typically cause more obvious/audible effects.  An instantaneous, "pop", usually harms nothing(but, one's stress levels).

order of operations should always be:

on: pre>amp off: amp>pre

@rodman99999 : Thanks for your response!  Yes it did sound right without any distortion of any sort.  I was just concerned if the drivers were cracked or is out of alignment.  The pop was so loud that it causes an immediate chill to my spine(hence a spike of my stress level) when that happened.

@bstatmeister: thanks!  Yes I was aware of the turning on sequence but completely forgot my amps were still on after done rearranging the cables.

@rogerhifi as stated above if things sound ok you should be fine. I did something even stupider a week ago. Reinstalling my streamer I ran one of the analog outputs to my DAC instead of the digital coax output. A very loud screeching sound launched me across the room to turn everything off! No harm done there either thankfully.

@jond LOL... I feel like we are going to turn this thread into "what is the dumbest you ever did to cause severe damage to your stereo..."

@rogerhfi Great thread idea!

@jond lol.

Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off. Power amps: Last on; First off.  I will not write on the blackboard one hundred times: Power amps: Last on; First off.

";o )

Okay, my turn.  I plugged a speaker level output* from one amp into the output of another power amp.  Blew up all the output transistors in the second power amp. 

*or maybe that was a line output into another line output ?  Have succeeded in forgetting the details. 

“on: pre>amp off: amp>pre”

So when using 12V DC triggers to your Amps from the Pre-Amp the power on order is satisfied, but not the power off? 

This is the way I’ve had it wired for ~ 17 years. Am I risking anything for this convenience?

Thanks

@choppi2003 congrats you’ve earned your star on this one.

@dunedain might want to check with the manufacture if the logic of orders reverse during power on and power off.  If the trigger functionality is provided for preamp and amp the manufacture should already take the sequence during on and off operation into account.

Thanks. I’ll check the manuals.