Yes power conditioners have always improved the sound of my system. This is true for the vast majority of people but not all. There is a very small minority that seem to live in exceptional locations with good power.
I have used a power conditioner for over 30 years in different locations. Isotech is an excellent choice as is Shunyata. You want to plug your amp directly into an outlet (preferably a direct line) and the rest of your equipment into a power conditioner in a different (preferably a direct line).
Just a comment on noise. Noise in audio is seldom heard directly… it is not a crackle or something you can focus on. It is the noise floor that unless you have a lot of experience is pretty invisible until it is lowered. The background becomes darker and you can hear deeper into the music. A power conditioner will also remove a layer of subtle distortion and also make the music more dynamic.

