[lanchile]

Hello, I was wondering if it will be a good idea to install one or more ferrite beads on the power cable of my amp. I hear some people that say it will affect the impedance of wire?
Should I put one or more on the power cord.

Ps: my power cord already has one installed from manufacture.

[OTM]

I guess the question would  be what do YOU believe the improvement in sound would be?
Many choices out there  that will or might effect sound quality.

[Zuman]

I was under the impression that ferrite beads were only effective at filtering out frequencies far above that of AC power. I may be wrong about this...

[Speedskater]

Depending on the ferrite material. over 100 kilohertz or 1 megahertz.
If you install a ferrite choke, install it as close to the chassis as practicable.
All the conductors most go thru the ferrite. (mic level signals excepted)

[Hydro]

I have found that ferrite beads work best on anything that has a computer in it. eg dac, master clock....I use them on my analog equipment and I "think" I can hear a difference. Tried them on my spdif cables and it softened the sound  way too much. 

[R. Daneel]

Actually, the proper term is "core", so ferrite cores, not beads

They filter very high frequencies, hence their typical application in computer and data trasfer -related peripherals. AC is either 50 or 60 Hz, depending on location, so a ferrite core in such an application will not make any difference.

Keep in mind though, even applications where ferrite cores can be useful, like the aforementioned data transmission, their effect is very limited and if a system depends only the ferrite core doing its job, it is more likely that it will not work than that it will. I am talking about industrial applications and electrically and/or magnetically harsh environments that most certainly do not include typical households.

Because you mentioned your power cable has a ferrite core installed on it, my guess is that you probably spent already too much money on the power cable. There are better place to spend your money with far more noticeable return on your investment.

Cheers!

[Speedskater]

Decades ago some power cords for printers and desktop computers had ferrite chokes. The power cords were acting as interference transmitting antennas. So the chokes were added to pass FCC tests.