Ferrite cores - why don't cable manufacturers fit them?

£££££  $$$$$  €€€€€

Simplz

Id be surprised if £££ was the reason.  The cores are very cheap and are fitted to the extremely cheap cables that come with computers, cameras etc.  Maybe aesthetics?

Hi Scott.  So there are some enlightened manufacturers out there

OK my response was maybe a little tongue in cheek - so some more serious thoughts.  

Most cable makers don't make the cable; its bought in on a roll from the actual cable manufacturer & is assembled to the plugs & sockets on a small assembly line.  Many of these assembly lines are low cost/tech & installing a ferrite to make it an integral part of the cable assembly is adding a task & cost that they are probably not equipped or willing to go to. 

Then add to the equation that some quarters believe ferrite kills SQ & maybe better sell a cable without ferrite than alienate a small sector of potential marketplace.  

Then add that most consumers don't care or can't hear a difference in a ferrite loaded cable & will probably go for cost or looks or ???? 

Thoughts on anti-ferrite - they don't know how ferrite works & that their effective frequency from 25MHz & upwards is out of range for even their golden ears.

Graeme- if you are wanting to impede radiating RFI from the cable - then put the choke on the noisy end - usually the source.

However if you want to impede RF ground current entering the end device - then the best place is at the end of the cable - near the DAC etc. So try experimenting at both ends- but certainly at the end closest to the audio source. (which probably is not the noisiest end....).

Simon

Thanks Simon - I notice Maplins have various ones at £2.99 - Any specific size requirement for DC1 and Cat6 ?

Worth a punt I'd have thought at that price.

G

Graeme,  I have ferrite on both ends of my ethernets two per cable = 4 along the NAS-NDX route; also one on the wireless hub ethernet at the hub end.  

I use TDK round profiled split clamps, longish length & slightly narrower OD than others but its mass (weight) rather than thickness that gives the impedance

Can be bought as singles or packs of 5 or 10 from Amazon or the bay.

Many thanks Mike.

G

Was just reading on acoustica site regarding filters and they state

"unfortunately the insertion of such a filter seems to squash dynamics and the natural, rhythmic expression of music; this applies to ferrites on cables too."

Has anyone noticed any detrimental effects by adding ferrites.

Graeme

NO

Like I said in a previous post ...........

........... don't know how ferrite works & that their (ferrite) effective frequency from 25MHz & upwards is out of range for even their golden ears.

In my Linn DS days, one of the popular mods on the DS players was to remove the Ferrite core on the mains cable that ran between the power inlet IEC connector and the SMPS PSU board (Dynamik PSU in Linn speak). A 10 minute job. The result more pace and detail but to my ears, a rather hard sound. I suspect what was happening was the crap being fed out via the mains or radiated via the mains lead gets in, and generates intermod products in the amplifier, the increased detail actually down to distortion.

After a few weeks i replaced it 

Simons advice makes a lot of sense. Ferrites are cheap so it's worth experimenting with them to see what works for you. 

I have them on my ethernet cables. May get some more to try out. To be honest I've not done any comparison, its too fiddley to take em on and off. 

Will try them on the mains leads too.

Graeme

Would the use of shielded ethernet cables obviate the need for ferrite cores or would they still help To reduce RFI?

I understand a screened Ethernet can carry common-mode currents (RFI) if not terminated (grounded)  & a ferrite will increase the cable's impedance to these currents.  I am sure more knowledgeable peeps will confirm or reject my simplistic understanding of this. 

I also understand if no CM current exists the ferrite does nothing & has no effect on anything & thats why I use them - to be sure to be sure. 

I'd leave screened Ethernet to industrial environments. Not needed in a domestic environment.

Oh ok, thanks, James

Mike sums it up correctly to me. A choke should have minimal if any impact to the signal carried within coaxial  or a balanced lead.

Simon, ok, thanks.  I'm sure I read on another thread that you said you could hear the benefit of a ferrite clamp on a DC1. Maybe I misunderstood.

Philp, I can certainly hear the benefits of choke on the DC1 from my NDX to my Hugo and NDAC before it.. But it is almost certainly impeding the RF circulating current / voltage on the shield.. However the digital signal carried by the central conductor will have minimal if any impact from the added inductance to the shield from the choke.

Simon

Ok, thanks for the clarification.