Amp Power Conditioner or not?

This thread raises the question, what exactly is "bad" power? Voltage fluctuating beyond some limits? That's a common criterion I see frequently cited as something a power conditioner can fix. What else might characterize "bad" versus "good" power? I'm asking because it would be helpful if there were a way to measure the goodness/badness of the power, before investing in a device designed to correct the badness. The logic is pretty simple: If test reveals no badness, then do not purchase a device designed to correct such badness (tacit premise: don't purchase something you don't need). Look, I know many will respond, "You have to listen to your system to hear the effects of bad power and what a power conditioner can do." If that is the response you want to make, please refrain. Unless I am way off (in a way that is hard for me to comprehend), I believe power conditioners are designed to correct certain, clearly defined and testable conditions in the AC power coming out of the wall. What *exactly* are they fixing/tweaking/adjusting in the power, and how can I check my power to see whether the electricity coming out of my walls needs such fixing/tweaking/adjusting?

Another reason to use a power conditioner and the reason that I do is not to clean up the AC but to protect my system from spikes. I live in an area where the power gets knocked out at least 2 or 3 times every winter due to storms and when lines get knocked out it creates voltage spikes thru-out the entire system.

Jiminlogansquare...it's my understanding that power conditioners do not just fix/tweak/adjust, to use your words, the power from the wall but also address issues created by our equipment as well as interaction between all the equipment as a whole. as far as how to measure it, i have no idea...

Way back quite a few years ago I had a Sunfire true subwoofer that added more than just extra bass.
When I unplugged it from the wall and out of the system, the music was much easier to listen to and it seemed as if there was less distortion to the music.

My friend is an electrical engineer and he brought over one of his tools of the trade and sure enough that Sunfire sub was spewing all sorts of nasty spikes into the system.
Taking it out of the link and out of the wall plug, and the print out was more clean.

So, that brings us to just how much noise and "bad" things are poluting our audio systems that unless you see it on a print out, you'll never know is there.

But it is there all day, 24/7, just less when most people are asleep, hence the "system sounds better late at nite" syndrom.

I run my class D power amps into a Shunyata Hydra 2, using Annaconda power cords all around and into a dedicated 30 amp,line.

I run all my source gear into a Furman balanced power condition, IT 1220(20 amp)from another dedicated 20 amp line, both on the same phase at the panel.

There is absolutely no noise, hiss, hum , buzz, or snap crackle or pop from my system and it sound as good during the day as it does at nite(well maybe not quite as good).

The best way I have found to find out if you need to do some kind of power conditioning is to try some of the good ones(yes the expensive ones, not the power bar, computer type spike suppressors)have a listen, then go back to wallplugging and have a listen, and then put the power conditoner in for a final listen.

You only know how much the PC's are doing ,when you take them out and then re-insert them.

Personally, my system has never sounded so good until I took care of the power going into my gear.
Next to doing something about room taming,getting the power"cleaned up" to my gear has made more of a noticeable improvement than any recent interconnect or speaker wire changes have.

As noted elsewhere,cheap power conditoners on amps that they were not designed for has given all power conditioning a bad rap.

Bryston never subscribed to using a power conditioner on any of their amps, but now endorse the Torus line.
Yes they sell Torus,but until it came along nothing really worked on their amps.

All I will say if you can even Home audition a Torus,
I quite confident,you won't want to take her back.
They are that good and the improvements are Superb.
They are pricey,but for MUSIC they are well worth it.
I have tried a few others,one that everybody knows and the Torus leaves it way behind.
Some of them will let you have the 15a or 20a from the wall,
the Torus will give you 50-400a(short term)when the amps want
it).That makes a HUGE difference the way the music is played.
If it came to selling a component or amp,I'd sell those and keep my Torus(s),they're that good.
It's free to audition and then you will know.