Power conditioner types


Do any power conditioners actually store the energy from the outlet/power company and then generate it on demand or do they all filter the current as it is coming through?

Or is it more complicated than that?

If any do store it, are they a different class?
sokogear
One cannot stress, enough, the need to remove any and all DC. The tiniest amount sets your tranny a buzzin even for several seconds after it's gone. It's what lots hear when they invest in a mega power conditioner with it's own tranny that doesn't address the issue properly. 
Or so I've read. My Niagara 1200 does, as does the Puritan 156.

All the best,
Nonoise
+1 Nonoise
Yes, Direct Curent removal is a winner.

What does an alternating current with direct current look like on an oscilloscope?
Instead of the alternating current rolling up and down across a zero potential line, the alternating current rides up higher, and the median of the wave rests on the direct current value.
Out of six or eight different brands of power conditioner that I tried, the Puritan PSM 156 was the only one that made an audible improvement to the sound.  This was immediately noticeable, and better in every way.

Puritan's power cords are also nice too.
Looks like I'm getting the Puritan 136. For my SS amp, it has more than enough capability. Thanks @hshifi - silver it is, and supposedly it will improve the sound over the Furman 15i.

@twoleftears - did you try the 136?
I have a PS Audio Power Plant Regenerator. I hunted it down and convinced the owner to sell it to me. One of the best things I have ever bought for my system.
Real black background, and this is through my all Tube system. Magic really. ;)