Question about coil whine

PSUs: The source of DC power for all components in the PC & often a big noise source.

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memory_leak
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Question about coil whine

Post by memory_leak » Fri May 13, 2016 3:05 am

I still haven't purchased a new PSU, but I am still thinking about getting Seasonic fanless 520W unit.

I did a research on Youtube and found few videos where people have recorded coil whine. I also found some discussion on the web where a person tried to RMA his PSU because of the noise it produced, but Seasonic sent it back with notice that nothing was wrong with that PSU. I checked info on their webpage, and they do market it as defined by "complete silence" https://seasonic.com/product/platinum-520/, so I sent a mail to check if I am eligible for RMA if my unit result in buzzing, crackling and other noises avialable.

I got really fast and friendly answer from real human with name Walter, within minutes of posting a question through the mail form on their page. Here is answer I got:
Please note the PSU may react differently based on system configuration and coil whine can be the result of MB or VGA card’s non-compliance to Intel standards for dynamic load.

As well, the fanless units have been updated and therefore should not have any issues but if you do experience coil whine and or strange noises, please note, the distance to measurement is 50cm, then please contact us and start a RMA here: http://www.seasonic.com/rma/
(I have cut out non-essentiol parts as greetings etc.

I asked him back if I can somehow determine which products are compliant with that Intel standard, and here is answer I got back (edited to bare essentials):
Sorry there are so many MBs & VGAs on the market and each with so many revisions it is nearly impossible to keep up.

A quick bit about dynamic load profile….. this is mainly focused on the 12V rail, for example with a VGA, if there is heavy graphics usage, then possibly the uptake and the drop of the 12V rail by the VGA will be very fast due to the quick change of graphics etc. This speak of change on the 12V rail must be within a certain guideline set forth by Intel and if it exceeds the range, then the PSU cannot react fast enough and a by product of this inability to react is… the expansion and contraction of the coils on the windings resulting in… coil whine…
I interpret this answer as if it this load on gfx card i combination with certain mobo will give same result from any PSU, not only those fanless, but maybe it is more perceived from a fanless PSU. I am not an engineer myself, and have not much knowledge about electrical components, so I can't either confirm or negate that explanation, but I suppose there are more knowledgeable people here who can give more details about coil whine.

My question is, have you noticed coil whine with other PSUs, and is there any way to know what components will work fine together other than trying them out?

edh
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Re: Question about coil whine

Post by edh » Fri May 13, 2016 4:26 am

There is certainly truth in the combination of components causing coil whine in some circumstances. I used to have a 9600GT which made quite a bit of coil whine under load when connected to an Enermax Modu82+. Changed to a Seasonic and it went away.

Some individuals have reported progress by covering components with superglue. Basically by fixing the thing solid it can't make the high pitched vibrations that we hear as coil while. YMMV.

CA_Steve
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Re: Question about coil whine

Post by CA_Steve » Fri May 13, 2016 6:47 am

memory_leak wrote:My question is, have you noticed coil whine with other PSUs, and is there any way to know what components will work fine together other than trying them out?
1) My two Seasonic PSUs haven't whined with their 3 different mobos and 4 different gfx cards over time.

2) Sadly, no.

Abula
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Re: Question about coil whine

Post by Abula » Fri May 13, 2016 8:27 am

memory_leak wrote:My question is, have you noticed coil whine with other PSUs, and is there any way to know what components will work fine together other than trying them out?
Coil whine will always be present in all electronic components, the questions is is weather its loud enough for your ears to perceive it. All PSU will have it, but in some is more prominent and thus you get more comments than others, that said, with seasonic it became a more common problem, personally i own a ton of seasonic PSU, and have built on a lot for friends, and till today, i havent heard one that has the issue others mention, that said we all have different hearing capabilities and frequencies that bothers more than others... so its just for you to test and decide.

Zolishoru
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Money, what else?

Post by Zolishoru » Sat May 14, 2016 11:27 pm

Coil/capacitor whine is a relatively well studied phenomenon; it can be controlled during manufacturing phase(or later, with warranty issues) with RTV Silicone or conformal coating.
But like any extra step during manufacturing, in the race to the bottom, the extra will be the first eliminated.
/back to lurk

memory_leak
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Re: Money, what else?

Post by memory_leak » Tue May 17, 2016 5:12 am

Zolishoru wrote:Coil/capacitor whine is a relatively well studied phenomenon; it can be controlled during manufacturing phase(or later, with warranty issues) with RTV Silicone or conformal coating.
But like any extra step during manufacturing, in the race to the bottom, the extra will be the first eliminated.
Hi lurker, is RTV silicone anything you recommend home users to play with?

Zolishoru
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Re: Money, what else?

Post by Zolishoru » Tue May 17, 2016 7:09 pm

memory_leak wrote: Hi lurker, is RTV silicone anything you recommend home users to play with?
I would recommend to try conformal coating(polyurethane based) first; surprisingly, in the most cases is enough; it was the go-to solution to silence whining flyback transformers, which wasn't exactly small(up to 15X15X15cm, 2kg). If you decide to use RTV, use acid-free RTV only.

quest_for_silence
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Re: Money, what else?

Post by quest_for_silence » Wed May 18, 2016 2:54 am

Zolishoru wrote:I would recommend to try conformal coating(polyurethane based) first;

How do you apply it?

Zolishoru
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Re: Money, what else?

Post by Zolishoru » Wed May 18, 2016 7:52 pm

quest_for_silence wrote: How do you apply it?
Small paint brush (if coming in bottle; don't forget to get the remover/thinner), or directly from the spray can. Typical painting guide applies: apply a couple of thin layers instead of a thick one. Cover the problem part completely, especially between the part and the PCB(a speck of dust can get in there, and cause the problem). Recommended viscosity to paint: ~light cooking oil. Take extra care of the application, because the coating is a pretty good thermal insulator.

memory_leak
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Re: Money, what else?

Post by memory_leak » Fri May 20, 2016 9:38 am

Zolishoru wrote:
quest_for_silence wrote: How do you apply it?
Small paint brush (if coming in bottle; don't forget to get the remover/thinner), or directly from the spray can. Typical painting guide applies: apply a couple of thin layers instead of a thick one. Cover the problem part completely, especially between the part and the PCB(a speck of dust can get in there, and cause the problem). Recommended viscosity to paint: ~light cooking oil. Take extra care of the application, because the coating is a pretty good thermal insulator.
Thanks for explanations. Is there any chance you could do it in a YT video,, with a demonstration before and after? Maybe someone could donate a noisy part, I could donate the silicone or whatever the paint thing is :).

Zolishoru
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Re: Money, what else?

Post by Zolishoru » Fri May 20, 2016 9:39 pm

memory_leak wrote: Thanks for explanations. Is there any chance you could do it in a YT video,, with a demonstration before and after? Maybe someone could donate a noisy part, I could donate the silicone or whatever the paint thing is :).
If you can convince somebody to do&upload the video, I'm all in; I even have the old PSU offered for science, and access to polyurethane conformal coating with thinner/remover and acid-free silicone RTV(black, transparent and white).

hochichi668
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Re: Question about coil whine

Post by hochichi668 » Mon Jun 06, 2016 12:01 pm

I did a recent build with a Seasonic 520W Platinum, and to my great disappointment, it's got the problem. The funny thing is that it didn't begin until about 2-3 days in. My set-up is an open air mobo with NoFan CR95C and the power supply on the tabletop next to it. At first when the whine began, it would disappear if I gently picked up the power supply or just gently applied pressure with my fingertips to the top of the box.

But in the past week or so, it's become constant. To really hear it, you have to be within 1-2 ft. of it. But once you've heard it up close, you're sort of trained to recognize it, and even though my PC is across the room, I can now always sort of hear it.

I can't decide what to do with it. I'd hate to return it to Amazon and be without a power supply for two weeks. Especially when there's no guarantee that a replacement wouldn't have the same problem. It's a nice power supply in all other respects. The silence the first couple days was a beautiful thing though. Now not sure how to proceed.

memory_leak
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Re: Money, what else?

Post by memory_leak » Mon Jun 13, 2016 9:03 am

Zolishoru wrote:
memory_leak wrote: Thanks for explanations. Is there any chance you could do it in a YT video,, with a demonstration before and after? Maybe someone could donate a noisy part, I could donate the silicone or whatever the paint thing is :).
If you can convince somebody to do&upload the video, I'm all in; I even have the old PSU offered for science, and access to polyurethane conformal coating with thinner/remover and acid-free silicone RTV(black, transparent and white).
There is a sticky thread asking for old parts to be donated and tested on SPCR. Maybe it is something for Mike C. to make a video of?

Just for the record, I decided to bite the bullet and bought one 520W. I can also repport that there is sound comming out of it. It sounds like there is a small fan, a tiny buzzing sound emiting out of it. It is more loud than my Noictua dh15 (with only one fan spinning).

I believe it is false marketing as they are marketing them on the website: "The Seasonic Fanless power supplies are defined by their complete silence" since they do produce sound and thus are not "complete silent" as it seems from most users. https://seasonic.com/product/platinum-520/

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