DougMac
Super Member
To me, this is a case of attributing a real experience to an unlikely cause when there are much more likely candidates. It is likely that there is less demand on the grid in the wee hours, but that's also the time you're more likely to be relaxed and focused. There's also probably a lot less environmental noise...just seems to me that the music sounds a bit better when there is less traffic on the grid, in the wee hours.
I work a decision tree from most probable to least probable and in this circumstance, I'd go through a lot of other factors before I'd get to power grid traffic as the reason my audio sounded better. Audio engineers are well acquainted with the vagaries of the power grid and any decent audio equipment has robust power supplies designed to handle a less than perfect power input.