Do your lights dim when your amp powers up?

I’ve had amps that flipped the circuit breaker if you powered both up at once. So it can happen. 

Very strange that you have a dedicated line and the lights dim. Mine do not. Better get the lines checked OR move the amp to another room and see if the same thing happens. Good luck and I hope you are able to figure it out sooner than later.

Very strange that you have a dedicated line and the lights dim.

This.

What amp do you have?

Yes, mine do as well. I have 500,000 uf on both the positive and negative power supply rails on the big amp and 300,000 uf on the mid and tweeter amplifiers. Slow start circuits on all the supplies, but it will still pop the 20 breakers on occasion. Thanks for the suggestion to check the connections at the main panel...

Hmmm, lights dim when you flick on your 8000 watt class A amp (no sliding bias).
Wonder what it could be?