Calling Simon: Ferrite Chokes

Hi - the choke should be sized to clamp around the coax or UTP cable. If the cable is thin, then yes you can loop through the choke for more attenuation. If there is severe RF current on the shield or in common mode then you can saturate a choke- but that is not going to happen here....

As far as each end - there are differring benefits for either end - or both. I however tend to clamp the choke around the receive end

Simon

Just an additional caveat,

If looping coax or Ethernet cables through a choke use big open loops as tight bends compromise the dimensional stability and performance of the cable.

P.S. I have ferrites on both ends of most cables - probably overkill, but they're cheap;  Someday I may experiment to find which ones are necessary and which ones I can redeploy (but I really can't be bothered!).

ditto ....... I have one on each of the ends of the 3x ethernets radiating from the switch.  

Ferrite on the 230v supply to the power strip loaded with x3 SMPS's,  the separate 230v to the NAS SMPS.  Then at least one on each SMPS DC out,  & each has at least 4 turns (passes) through the ferrite,  & finally one on the phone line to the phone & another to the wireless hub,  each with 5 passes around the ferrite. 

- lets say I have no intention of finding out which ones are not needed.  

Ditto, I have them all over the place and, to be honest, I can't say that I can tell the difference but for the very low cost why not, better safe than sorry really

Hi dayjay,

I can certainly tell if I play certain pieces of music - particularly some Baroque orchestral pieces.  With these the Harpsichord disappears when it should be quite audible, as the amount of low level clutter rises and overwhelms it.

one naive question: given all the benefits any reason why aren't there cables with the chokes already included by the manufacturers in the first place? 

Great minds think alike

https://forums.naimaudio.com/to...nufacturers-fit-them

1   Cost

2   Consumer acceptance

Some people believe that ferrite chokes will 'squash' the dynamics of the sound even in a screened cable.

What surprises me more is that manufacturers haven't taken standard cores (maybe 20p-50p each in bulk), fitted them into a more fancy (and possibly damped) plastic clip on housing, called them 'Audiophile RF Suppressors' and sold them for £20-£50 each!

and in the pro world many are....

But only if you have seen a single Magpie in the garden on its own...

thanks PhilP for ponting this thread out

Dears, apologise me in arise a new question.

Re-reading the old posts and this thread, I assume that ferrites are fine with ethernet and power cables.

And so, why it isn't necessary to the interconnect between pre- and power-amplifiers?

Or can be used in base of the same principle? Theoretically all the chain should be 'cured'?

Well, once I've asked it to Mike by email... :-) But maybe it could be of general interest anyway.

Have a nice music weekend!

I have them everywhere...

Mains

Ethernet (remember don't bend the cable sharply)

Interconnects

S/PDif cables

SMPS

As I don't use NAC A5, I even have some on the speaker cables in differential mode!

Bicela, good question. The chokes are designed to impede common mode or shield RF currents by adding inductance. Therefore you would typically apply where there is a propensity for such RF currents.

Now in some scenarios you may well have RF currents passing through the interconnects, and if shielded or balanced, then a choke might indeed work, but there are better options to mitigate RF in interconnects such as using certain products from DNM that specially terminate both ends of the interconnect within the plugs.

However conventional wisdom appears to show its better reduce RF before it gets to the delicate audio signal interconnects...

However when I used a turntable, I wound my cartridge wiring around a ferrite ring before going into my phono preamp... because of the smaller voltages and the propensity for the cartridge wiring shield to pick up ambient RF this proved beneficial.

Simon

Thx Simon / all

Thanks Huge, thanks Simon and thanks Mr Underhill for posting.

Sorry Huge, could explain it better?

As I don't use NAC A5, I even have some on the speaker cables in differential mode!

Hi bicella,

I use a Nait XS, which doesn't require the inductance of 3.5m of NACA5 for stability.  However it will react badly to cables with low inductance & high capacitance.  I use Audioquest 14/4 SLiP which is a quad star cable medium inductance & medium capacitance.

The differential chokes increase the inductance at frequencies above the audio band, giving the amp an easier time.

Simon, as per the recommendation of the title of this thread (), are you going to consider changing your forum user name to "Ferrite Chokes"? 

Sorry Mr Underhill, I just couldn't resist using your thread title for that joke suggestion.

Many thanks Huge,

I'm begging your pardon again, really my ignorance don't allow me to understand what is practically the "differential chokes" (how they are clamped and where)...

In what it is different to clamp one ferrite on the both sides of a cable? Differential should have a meaning here that I lost... Sorry.

Hi Bicella,

No problem.

If you have a cable with two conductors, current can flow in those conductors in two ways:

1  The currents in the conductors can flow in the same direction: This is common mode.

2  The currents in the conductors can flow in opposite directions: This is differential mode. 

A common mode choke opposes common mode currents in the cable - both the conductors go through the choke in the same direction.  This is how clip-on ferrites are most often used.

A differential mode choke opposes differential mode currents - the cable is split and the conductors go through the choke in opposite directions.