Ferrite Cores for Power cords

My experience, works well on a pc for digital, not so good on pcs for preamp or amp. I found when I tried them on the preamp or amp it caused the sound-stage to collapse somewhat. Just seemed to take the life from the music. Just a note here, my preamp and amp are tubes.

For the CDP it helped in two ways. It helped stop RFI from entering the unit through the pc and stopped the RFI generated by the CDP from going back out on the pc. I also found they worked best when installed on the pc where it entered the equipment.

Jea48, I have tried ferrite clamps extensively everywhere and you are indeed correct. Too many and it sucks the life out of a system. I think the best place to use them is on the power cord on the cdp. One on each end. Someone sent me a Analysis Plus Power Oval 2 with a ferrite clamp on each end and WOW this cord is extremely musical this way. Take the clamps off for a few minutes and more grain is added. It was very noticeable. This cord was not good on the amps but great on the cdp. My recommendation is to start at the cdp and work your way down. My system has changed recently so I may go and throw a couple of clamps on the ic's from cdp to pre. If the sound darkens or closes in they will come right off. I have not played around with these for a while except when I received the power cord I am using now.
Find a real good price on a used Power Oval 2 and put two of the box type ferrites clamps on it. I don't think enough can be said about rfi entering and exiting the cdp.
Digi-key has all kinds of ferrite clamps too.

These devices act as a choke (filter out higher frequencies that may be picked up as a cable acts like an antenna).

Generally these should not be required on a power cord or speaker cable as impedances are very low (unless you have a radio operator next door with a big antenna radiating you). The most useful application will be on video monitors or data cables that operate at high frequency with low signal levels and high impedances.

wilfredt, after reading this last night I played around with some of the ferrites I own. I tried 3 in the basement on my 20 amp circuit that powers my system. This was a nice improvement. More natural and smoother.

I also tried 3 on my virtual dynamics cable for cdp. One clamped on all 3 cables of the virtual power cord. This was another nice improvement. same as noted above.

I actually orded 60 of these on ebay and they seem to have the nicest prices. I bought some larger 11mm openings and larger ferrite to get more of the larger cables.

nice and worth the little expense considering how much these places sell their tweaks for.

Dear all, thanks a lot for sharing your experiences. I conclude it is definitely worth a try placing at different places mainly close to the CD player, especially considering the low prices involved. I shall buy some from the online sources you mentioned to play around with them.

Freemand, I could only locate one Hong Kong based source in ebay - did you buy from the same source or was there another one too.