Has a Power Conditioner Improved Your Sound?

Isolation transformers sure do.

@ghdprentice says, 

Noise in audio is seldom heard directly… it is not a crackle or something you can focus on.

Well said. My experience exactly.

Most of the power conditioners I've tried have produced a positive result. The one exception was Richard Gray's Power Company products. I pretty much went all in with this product line and could never get the results I was looking for.  There was a negative review of this in either Stereophile or Absolute Sound (I can't remember now) and the problems sighted were exactly what I was experiencing. I know there were those who voiced their support, so perhaps it is/was system dependent.

Has anyone had a negative experience with a Furman 15i power conditioner? When installed in my system it seem to roll off the top end. It took the ‘ sparkle ‘ out of the sound . However I did like the Active voltage readout where I could see the fluctuations in incoming voltage. 

Years ago my Paps used to go to the same phone repair guy for all his needs.  He sent my Paps home with what he thought was a broken UPS.  So Dad said I could have it if I wanted to try and fix it.  I opened it up later and saw the huge transformer and cars, etc  and realized this was a line conditioner.  More specifically an Ametek PowerVar.  It was the medical version.  I took it home and put it behind my listening rig, and it did in fact make my silence blacker, and felt clearer overall.

But my entire apartment is on a single 20A circuit so my place was a true candidate for a unit like this.