Have you ever hated the sound of your system one day, and loved it the next?

It’s a common  phenomenon that certain times of the day there is a greater demand from the power grid and early morning and late evenings there are sonic differences because there is generally less demand. So during peak demands we find the age old saying, Garbage in garbage out.
some power conditioners do a better job than others do but I don’t have the experience to tell you which is better than the other! 

durkin
I joined a Facebook group called tube rolling and have just started playing around with different tubes and have found a vast difference.
i also made an investment in something called Total Contact by a company called 
Perfect Parh Tecnologies and the results have just blown me away!!!!!

yea! it wasn't broken in and than next day OMG!

I think the biggest difference is YOU. Depending on how much dopamine you have floating around up there at any given time can influence what you are hearing tremendously.
I think the time of day/pressure/humidity/weather can play a role, but not as much as above.

Often. It is a holistic issue involving different levels of water intake, daily life experience, media format, speaker position, chair position, humidity, how many things are on my mind, what I had for my meals, first/last CD or LP chosen that day, etc. etc. etc. could it be my electricity? Sure, that too.

Often I will just find that LPs don’t sound good, or CDs don’t sound good. Rarely it is both not sounding good. Perfection is when both sound good equally. 

It is is important to both quantify and qualify/externalize and internalize our audio experiences. But we should never take it too seriously—unless it is our profession. If it isn’t your profession, I think it a good idea to turn it off and go for a walk.