What's Going On?? Sound changes every night

So I'm not the only one who experiences this!@#$%&

I think one of the biggest factors is components that are not fully broken-in and are going through "changes". But, having said that, I know I've had this happen to me with fully broken-in gear.

I swear sometimes I think I'm losing it and just want to scrap the whole program.
Next session, it's audio bliss!

One more soul weighing in... I've experienced this too, though thankfully not as frequently as Tomryan--yet as recently as two nights ago. Onhwy61 (Dylan fan, are you?) makes a really good point. And the electrical grid argument makes equally good sense--although I find if music isn't sounding too great on my main system at a given point, it often sound just fine on the bedroom system a few moments later. Maybe that means I'm in dire need of bed rest. Anyhow, the hell of it is, the better the equipment that I add to my system, the more pronounced the peaks and valleys become, when the valleys show up.

I have the same problem with my system. When it's good, it's magical. When bad, unlistenable. And it will change on a moments notice and back again. The entire bass spectrum will disappear and the top will get gritty and grainy. And it's not related to any particular component as it happens in 2 different rooms with a multitude of equipment

I looked into my house wiring, built in 58', and it's obvious that dedicated lines are a must. Typical home wiring consists of a few to a dozen or more splices involving twisting 2 copper wires together and/or push in connections that are nothing more than the edge of a piece of brass touching one side of the wire. In my home, they actually used aluminum pieces to crimp the 2 wires together.

Needless to say, the line resistance varies with the humidity, temp, and power used. Copper corrodes rather quickly and you can imagine what it's like after 30+ years.

I would not think of auditioning any power conditioning/power cords untill you have installed dedicated lines. Use 12ga romex and put one twist in the wire every foot or so to make it less of an antenna.

One other thing that I know effects my system is the power down of the AM radio stations at sunset. The radio stations are required to reduce power something like 90%.You can actually hear a layer of grundge dissappear about the same time each night. I initially thought this had to do with EMI from the sun lessening it's effects on the power lines after sunset. But it was way too abrupt-like flipping a switch and the time changed about a minute each night-tracking the daily change in the sunset.

In general, dedicated lines are less expensive than power conditioning and have a more positive effect.

"Copper corrodes rather quickly and you can imagine what it's like after 30+ years."

Actually, when copper "corrodes" it produces a conductive oxidate on the outside that should not cause problems by itself. Also the joints and connections should be fine too (see; the opposite problems with aluminium house wire that caused so many fires in the 60's and 70's that it is banned for house wiring)

More likely, however, are problems with insulation from older wire.

All the responses are much appreciated. Last night things were a bit bright as opposed to the perfect mix the night before and the rather dull presentation the two nights before that! This stuff just started about 3 months ago and is the same even while mixing equipment.

I do think it's most likely something to do with the power coming to my gear and I'm going to call an electrician to get a dedicated line and circuit. By the way, can anyone suggest an outlet that may work better than the hospital grade one I'm using now? And I will be getting a new and better power strip as I just realized the one I'm using is 15 years old! Any suggestions for one (I know PS Audio makes one - any users?)?

By the way, I do live at the end of a cul-de-sac in a 50 year old neighborhood.