Ferrite cylinder things

afterburnt

I just found these I am guessing by the size of them that they came with a power cord for something. Does anyone use these, if so where?

Thanx

msg

Your father obviously didn't use them properly.

F1nut

afterburnt wrote: »

I just found these I am guessing by the size of them that they came with a power cord for something. Does anyone use these, if so where?

Thanx

They can reduce/remove noise on a power cord. More commonly found on computer and TV power cords.

afterburnt

msg, I don't know who my father is but he must have been really stoopid cause my mom is pretty smart and look at how I turned out. Now that I think about it my mom wasn't all that bright for having sex with a we todd. But back to important stuff.

Jesse, there are some built into the HDMI cable that came with my Oppo but that is for video only so that should be ok no?

Derek, are you talking about on power cords?

ZLTFUL

https://en.wikipedia.org/wiki/Ferrite_bead

pitdogg2

I've used them both on power cords and interconnects. I didn't find any adverse effects with them. ymmv

pitdogg2

Its all good. A well engineered cable will not need any. I used them on braided cables i made and on over the counter well made cables. Ferrite is also what the AM antenna bars were made out of back in the day on old tuners. They can not only reject but attract stuff.

afterburnt

If there was a consensus on their utility I was gonna get some for my stock power cords since I can't get better new cords for now. I am guessing that you need a few per cord to get any benefit. If yall think I should use em please tell me where to stick it, uh them. Amazon has all shapes and sizes for a few bucks a piece if I looked I am sure I could find them cheaper.

txcoastal1

They work best on Dc input devices

afterburnt

Ok, I just didn't want to get on the floor for nothing and have to wait an hour to get the strength to get back up.

Ron, I am not sure if I have any DC input devices or Marvel input devices for that matter.

mhardy6647

superstrings?

lightman1

mhardy6647 wrote: »

superstrings?

Jstas

OK, time to put the "opinions" aside here and listen to real science.

Those ferrite cylinder absolutely do have an effect but you don't hear it. If you think you do, you're full of baloney so just step out of the thread now and learn something.

Those ferrite cores do not affect how the power reaches whatever you are trying to power. They stop surges from traveling back down the power cord and into your house wiring where they can do stuff like fry an expensive thing like a passive pre-amp or SACD player.

The surges are very real and occur when a high current power supply abruptly cuts off. That's why you see them often on stuff like circular saws or other power tools.

If you think of electricity as traveling in waves, picture water in your bathtub. The bathtub is full of water, that would represent the power grid. Your drain is the cord to whatever high current thing you are running with electricity. When the drain is open, the water travels pretty quickly to through the drain. Now snap that drain shut. What happens? Well, the water that was running to the drain kinda starts running into the water that was just heading down the drain that was abruptly stopped by the drain closing. It all rushes into the drain stopper. That causes a back wave to rush back through the drain opening and ripple out to the bathtub. That backwave is caused by all the water that is bouncing off the drain stopper. The bigger the drain, the bigger the backwave.

Electricity on a high current item like a circular saw or an air compressor or a power amplifier will behave in a similar way and can send a pretty strong surge when they are clicked off like you let go of a trigger on a saw or the air compressor's pressure trigger shut the motor off or you're done listening to your stereo for the night and shut off the power amplifier.

That back wave of a surge doesn't travel back up the power cord, though. It doesn't fight the flow of electricity down the power cord. It will travel on the outside of the cord, not outside the insulation but on the surface of the wire inside the insulation. Think of what it looks like when you're peeing in the toilet. The water doesn't come back up the stream and hit you in the wee wee, it gets push out of the way by the continuing stream. By the time you are done and the water can travel back up the path it came, there's not enough energy to overcome the resistance to get there so it falls back down to the toilet.

The ferrite cores are magnets. The poles are arranged so that anything traveling through the center is unaffected by the magnetic fields. The reason they are necessary is that the wire is a confined space and there's not much space for the return surge to go. So it can build enough energy to reach places where it can do damage. Just like if you were peeing in a water bottle that wasn't big enough to hold everything you had in you. It's gonna come back out.

What that ferrite core does is it chokes down on that pathway so that surge can't get past it or it's magnetic fields but it allows the flow of power from the grid to the power supply transformer.

That's why they are called chokes.

They are a cheap and effective way to prevent damaging electrical power surges. The vast majority of amplifiers don't have them because they don't need them. They have components on the power supply system that prevents that surge from going anywhere and even then, they don't draw enough current to be causing the issue. Something that will make your lights dim like a circular saw or a pair of Carver Amazings being driven by Silver 7's will do that. Silver 7's, though, won't send the surge back down their power cords. You're Milwaukee 7 1/4" circular saw will.

So they server a purpose and have no negative effect on power delivery to your equipment. There is science to prove it. If you use them on your interconnects, you're kinda wasting your time because the voltage and current is far too low to do anything of any consequence to the components that would handle that signal. If your interconnects are shielded then the chokes are doing absolutely nothing because the whole point of a shield is to prevent interference from EM sources.

Also, since the signal path is DC and not AC, a magnetic choke is likely causing interference with your signal path if you have them on interconnects so take them off. They are unnecessary and likely causing problems.

If you have it on a power cord, it's fine to leave them there. Just make sure if there are directional markings you have the arrow pointing in the correct direction of the power flow.

The reason you can buy them individually is because they can break. I have broken them before on my Milwaukee circular saw from stepping on the cord or something falling on it. If they break, it changes how the field works and it's not as effective if at all. So you replace them.

And I have seen actual effects on stuff like portable generators pop a circuit breaker from the surge the chokes are meant to protect from.

Jstas

Did you not read my post?

The whole point of magnets is to suppress power surges. Power surges, like all power transfer, operates on electromagnetic fields. That's why magnetic chokes work. Magnetic chokes are also directional. Installed properly they will not affect the flow power to your system. They should not be used on interconnects.

Stop propagating snake oil solutions. Anyone who tells you that they are a positive influence on any kind of sound is full of baloney. They aren't. They are designed to be that way. Unless your choke is loose and sliding down to near your component's power supply, the EM field is not strong enough to affect what the component is drawing. If you choke is sliding down your cord. shove it back up to where the plug is and put a zip tie around the cord behind it to keep it there.

If the magnet ends up near the component, it can cause a hum induced in the power transformer from the magnet affecting the EM fields in the power transformer if the transformer is not shielded.

steveinaz

Good to know jstas...I always wondered what the point of those were.

Jstas

Again, did you read my post?

Magnetic Chokes are for power cables. Not signal cables. If you have them on your signal cables, remove them. They will do nothing but cause problems.

I stated that directly in my post. Actually several times in now 3 posts.

I don't know why you are still trying to "educate" me on this when I've clearly stated it several times now.

And the design principle has everything to do with the application. If you are not using them as designed then they are not going to work as designed due to improper application and that can and likely will result in less than desirable effects that won't necessarily be predictable.

CoolJazz

I have never heard of a ferrite choke being used in the same sentence as "surge".

What they do is form a low pass filter. Much like using a disc cap on a line. The material used effects the frequency, which is why you can order ferrite rings for uses at different frequencies.

Using them on audio lines is questionable much like using any low pass filter is. The question in that case is what frequency is the pole and what bandwidth you have.

On a cord on a power tool, it'd be effective an minimizing the harm back onto the line from all the sparking at the armature (HF noise). And when you stop, maybe for an instant from ringing but I don't think that's really what they're for.

I disagree with much of what's been said here as wisdom and I've purchased and used ferrites in many high power applications.

CJ

CoolJazz

Also, probably better get used to them with all the junk out there on power lines today. Like the Obama bulbs, the LED lights, the switch mode power supplies hanging on everything, etc....
CJ

tonyb

CoolJazz wrote: »

Also, probably better get used to them with all the junk out there on power lines today. Like the Obama bulbs, the LED lights, the switch mode power supplies hanging on everything, etc....
CJ

Eh...like already stated, if you have a well built power cord, in audio applications anyway, you shouldn't need these things.

Jstas

First off, forgive me for using a descriptive term that may not have been 100% accurate but was used to describe something complex in simple terms so that one does not need an engineering degree to understand what I am saying. Just because it's a term you are not familiar with in relation to the topic at hand does not make it incorrect, though. EM fields, just like actual power transmission, can surge. It's how EMPs work.

Secondly, since you don't believe me, here, read about it yourself instead of just guessing about complex topics.

http://computer.howstuffworks.com/question352.htm
https://www.quora.com/What-purpose-does-the-small-cylindrical-module-near-the-end-of-my-laptop-charger-cable-serve
http://gizmodo.com/5871162/what-do-those-mysterious-lumps-on-your-cables-do
https://superuser.com/questions/217772/what-is-that-cylinder-on-cables
http://www.slate.com/blogs/browbeat/2012/11/01/cylinder_or_box_on_computer_cords_what_s_it_for.html

There's plenty more links all explaining it in simple terms from people that aren't me.

http://bfy.tw/CLNc

It's 2017. The entirety of human knowledge is accessible from a little glowing box in your pocket, 24/7. Ignorance is not an excuse now more than ever.

BlueFox

tonyb wrote: »

CoolJazz wrote: »

Also, probably better get used to them with all the junk out there on power lines today. Like the Obama bulbs, the LED lights, the switch mode power supplies hanging on everything, etc....
CJ

Eh...like already stated, if you have a well built power cord, in audio applications anyway, you shouldn't need these things.

That would be because a well built power cord has filtering built-in to it. This issue is turning into a cable debate.

At the end of the day, in audio at least, everything has an effect on the sound. Whether it is good or bad is up to the individual. In regard to ferrite cores on cables I think the fact that there doesn't seem to be much of a market for these items speaks volumes as to their effectiveness in the audio realm.

pitdogg2

they were used for a while Bud then they went away. IIRC on some cables they would drop the ohms way down and that affected the sound. Or was it too high I remeber something about ohms it was in one of the audio mags way back when.

CoolJazz

Jstas wrote: »

First off, forgive me for using a descriptive term that may not have been 100% accurate but was used to describe something complex in simple terms so that one does not need an engineering degree to understand what I am saying. Just because it's a term you are not familiar with in relation to the topic at hand does not make it incorrect, though. EM fields, just like actual power transmission, can surge. It's how EMPs work.

Secondly, since you don't believe me, here, read about it yourself instead of just guessing about complex topics.

http://computer.howstuffworks.com/question352.htm
https://www.quora.com/What-purpose-does-the-small-cylindrical-module-near-the-end-of-my-laptop-charger-cable-serve
http://gizmodo.com/5871162/what-do-those-mysterious-lumps-on-your-cables-do
https://superuser.com/questions/217772/what-is-that-cylinder-on-cables
http://www.slate.com/blogs/browbeat/2012/11/01/cylinder_or_box_on_computer_cords_what_s_it_for.html

There's plenty more links all explaining it in simple terms from people that aren't me.

http://bfy.tw/CLNc

It's 2017. The entirety of human knowledge is accessible from a little glowing box in your pocket, 24/7. Ignorance is not an excuse now more than ever.

Thank you for your concern for my ignorance. Greatly appreciated.

I looked at each of those links to lift my knowledge and they all seem to agree exactly with what I said as far as they go anyway. I see no mention of "surge".

Again, they are simply a low pass filter. That's what they do. Sorry if that's technical.

CJ

mhardy6647

lightman1 wrote: »

mhardy6647 wrote: »

superstrings?

afterburnt

Why are they on this Oppo HDMI cable?

CoolJazz

Some much more appropriate links for anyone wanting to dig in and understand ferrite chokes would be found among these....

palomar-engineers.com/ferrite-products/ferrite-cores

audiosystemsgroup.com/SAC0305Ferrites.pdf

https://proaudioeng.com/wp-content/uploads/2015/05/AC-Power-Supplies-and-RFI.pdf

premiermag.com/pdf/PremierMagnetics_WP_v2.pdf

https://coilws.com/index.php?main_page=page&id=128

ka7oei.blogspot.com/2014/08/completely-containing-switching-power.html

https://nonstopsystems.com/radio/pdf-ant/article-cost-effective-chokes.pdf

yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf

And some much more on audio topic comments in this CA thread than what we got above...

https://computeraudiophile.com/forums/topic/13258-use-of-ferrite-core-chokes/

CJ

CoolJazz

From the AudioSystemsGroup link....

"How many times have you heard someone say, "ferrite beads don't work on this problem – I added one and nothing happened." In fact, they were simply below the threshold impedance needed in that particular circuit!"

afterburnt

Thanks for all of the replies, l am just gonna put em on my coat hangers.

mdaudioguy

Jstas wrote: »

OK, time to put the "opinions" aside here and listen to real science.
...
And I have seen actual effects on stuff like portable generators pop a circuit breaker from the surge the chokes are meant to protect from.

Dude, I'm between semesters right now (last one ended 17 years ago), so I'm bookmarking this until my brain refreshes... maybe around mid-September, I'll come back and study this. I've always wondered about those things... just not so much at the moment!

BlueBirdMusic

Here's one for this thread.

jdjohn

Well, no one has mentioned RFI yet, except that a power cord can turn into a radio antenna. I have a Schiit Mani phono-pre, but I don't use because it picks up an FM transmitter that is a few miles away from my house. I put a ferrite choke on the power cord (looped it through twice), which helped, but still didn't eliminate the background FM entirely. This is actually a known issue with the Mani, but Schiit won't offer any solutions for it. Apparently they cheaped-out on the power supply (inadequate shielding). IIRC, the wallwart is actually AC, and the transformer to DC is inside the Mani...or something like that. Frankly, I wish they would get their Schiit together and offer, or at least recommend, a solution.