Thanks for the information, helpful to me in understanding what’s going on. The lights in my listening room are a set of six ceiling cans with fairly high wattage bulbs on a separate circuit from the sound system, and supplied by 14 gauge wiring on a 15amp breaker. Based on the discussion here so far, I am thinking the 20amp/10 gauge “pipe” supplying the amp is the path of least resistance, and robbing current from the lights when the caps charge coming off of standby, resulting in a very brief dimming. Not sure if the difference in gauge of the wiring makes that big of a difference in the amount of observed dimming, but I guess it’s possible. An easy test is to plug the amp into a different circuit that has a higher gauge supply wire and smaller amp breaker and see if the lights dim as badly. That would require a very long extension cord.
I will say that I have tried different amps and other components in other rooms in my home without dedicated lines, and even with headphones that remove room variables, everything sounds better on the dedicated line and the difference is not that subtle. I can put up with lights going down briefly on start up if it means the amp is winning the war for current! The amp I looking to buy is more powerful than this, so I guess I will just have to get used to it.
kn

