Sometimes my system sounds great, sometimes awful


Does this happen to any of you? Sometimes I find that my system sounds great, but sometimes, with the same record, same everything, it sounds awful! It drives me nuts. Do we hear differently depending the time of day, our mood, heat, cold... other circumstances? Whenever I think I have to replace a component or trash a cable I tell myself to wait until the next day to overcome upgradetitis.
vmm
Yes, in AZ during the summer with everyone using air conditioning I find the quality of AC power is bad it robs my system of smoothness, detail, and fullness. After 10pm at night it improves. Sounds best when it is cold outside!
I sometimes think mine sounds great. I sometimes think it sounds not so great, but never awful.
Completely agree with you, Vmm. Have you noticed if other systems, such as your car, also sound good or bad when your main system does?