[jhrlrd]

I'd like to build or buy a small unit that would plug in series with each component's power cord to prevent generated noise
from going back into the other components. All my gear is plugged into a line conditioner already.
Any suggestions? thanks

[jeffreybehr]

j, a simple 3-legged capacitive filter* at the component's AC-power inlet would reduce much high-frequency noise, incoming and outgoing.  Our resident experts probably will offer more-elegant solutions.

* Hot to common, hot to earth, and common to earth

[G Georgopoulos]

this link has c-l-c bi-directional filters for live-neutral (2wire) and live-earth-neutral (3wire) mains EMI/RFI filters
if you build it your self make sure caps are rated ac mains voltage

http://www.audiomisc.co.uk/mains/filters1.html

[jhrlrd]

Great link for the basic RF filters. But what about noise in the audible range?
like hum/hiss/buzz coming out of the speakers.
I have a big issue with noise the plasma TV is generating coming over the speakers.
When the tv is off I'm still left with noise from the tube pre and amp, to a lesser degree, but audible from the listening seat.