Use of Ferrite Cores for EMI Reduction???

I bought some rat shack ferrite cores for my CDP 'power cord'tuner power cord and pre power cord.cant tell any difference but I sure sleep better at night!

In my case the rf stoppers work best close to the pre amp.
I just added the paper towel wrap. Sounds the same to me.

Ferrite beads should only be used on wires not carrying the audio signal, where you are filtering out unwanted noise.(If you use them at all) The reason that made these peoples systems sound bad is the same reason shielded cables sound bad. The audio signal is AC which generates a varying magnetic field around the conducting wires. If you attempt to collapse or restrict this field, you will influence the signal that is producing it. If you MUST shield your interconnects, then try using unshielded interconnect (30ga. solid) wire inside a MUCH oversize flex tube wrapped with appropriate shield material and a drain. Preferably, each wire + and - on each run will have separate shielded tubes as their fields also interact, especially when buched right next to each other as in a standard interconnect. Standard interconnect topology is designed for convenience, not sound, even though high end mfrs. would have you think otherwise. Use tube at least 1 inch diameter with teflon discs to center the wire in the tube. Be sure to connect the shield to one RCA plug end only , as a drain.Or drain directly to a chassis mount lug. The dynamics will stun you.

Twl, the cables that you mention would be quite high in inductance. Then again, the treble roll off that takes place might somewhat balance out the somewhat leaner and brighter sound passed on by using such a fine gauged conductor.

I think that the guy that basically came up with ideas like this and pushed the envelope as we know it was David Magnan. He has gone to great lengths to minimize time smear, skin effect, etc.. in cables like nobody else that i know of. I've got a couple sets of his cables that make use of 36 gauge conductors that are air insultated and somewhat spaced apart. His newer designs don't even use wire at all, as they use some type of conductive "paint" to minimize skin effect. Never heard or used them, but some say that they are the ultimate. Sean
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Sean, please elaborate on your comment of high inductance characteristics for the cable I mentioned. I believe that as inductance increases with proximity, the 1/2 inch minimum separation of conductor to shield should be adequate to reduce inductance to a minimum. Larger separation would be better, but we must retain some level of ability to move the cable around. With the pos. and neg. each run separately in their own separate tubes, they would not interact with each other significantly. I am aware that inductance affects can be present from AC 120v power cables as far away as 1 foot, but in the smaller power levels present in interconnects I don't think the problem is anywhere near that magnitude. Also, I mentioned that I would prefer no shield, but was trying to address his RF splash problems.