How much does power grid load effect the sound?

in the evening?...me personally...I like it best around 4am when I have the majority of the grid to myself ;o)...damn...I really need to get back on a regular schedule.

but this depends on the equipnment alot also some is more prone to noise.

With the exception of the MPX indicator being a bit dim on my McIntosh MR71, there is no audible difference in my stystem at full power(121v)vs a typical 90+ day with all the local air conditioners running full tilt. (measured voltage drop at wall was 114v) Maybe it's because I have a tube system ??

Screw that...when YOUR audio gear affects the power grid, you know that you're cookin'!