System sounds better at night?


I have noticed that my system sounds MUCH better at night, after about 10pm than at any other time of day. It is clearer, more open and transparent, with a blacker background. Another audiophile told me that this is not real, it's just that there is less noise in the household at night. I disagree in that what I hear (or don't hear) is not simply due to less ambient noise but rather cleaner sound. Will power line conditioners simulate these effects during the day? Has anyone else noticed this and what is the most effective way to get better sound during the daytime? Serious responses only, please.
jc4659
For those who use the Inakustik AC-3500P, are you plugging your power amp into this conditioner?  What about your digital gear?
For my system, a pair of ATC SCM20-2 active monitors (built-in amps and x-overs), Jay’s Audio CDT2 MK2 CD Transport, Theta Digital DSPro Basic IIIa DAC and Oppo SE83 blu-ray player are plugged into the unit. My preamp, Teo Audio’s The Liquid Pre, is a passive unit that does not require power.
Since each outlet of the Inakustik AC-3500P is configured in parallel to the other outlets, all outlets have as much power line feed as the others. This is not the case with certain other conditioners (or so-called power distribution centers) in which the outlets are linked together in series (aka daisy-chained). In those cases, the first outlet served from the wall or internal circuit gets the feast of all available power while the last outlet in the chain gets the famine.