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Class D amp and SMSP coil whine?

CleanSound

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I have a pair of SVS SB-3000, they both suffer from very minor coil whine. It bugs me, because I am OCD like that.

My experience with electronics with PWM technologies such as Class D amps and switching power supplies often times suffer from coil whine.

Yet, I also have a DIY Hypex NC500, dead silent.

Anyone else with coil whine on their class D or SMSP?
 

fpitas

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Probably a squirt of RTV would fix that. Use the electronic grade.
 

DVDdoug

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Most likely it's a coil in the switching power supply (not the actual amplifier circuitry).
 

fpitas

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I'm a little surprised the frequency is low enough to be audible. But silicone goop fixes all.
 

jonfitch

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Wait you just squirt it directly onto a circuit board? No downsides to that? All the videos I’ve seen of fixing coil whine on video cards and PS5s look a lot more complex from professionals.
 

fpitas

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Wait you just squirt it directly onto a circuit board? No downsides to that? All the videos I’ve seen of fixing coil whine on video cards and PS5s look a lot more complex from professionals.
Our production guys just clean things well and squirt it on. They seem under the impression they are professionals lol.
 

Trangbar

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This is excellent information! I have a SVS 3000 Micro that has been whining since I have bought it (2nd hand) and was thinking to contact SVS as I heard they sometimes replace the amp module to address it. I am going to give the silicone goop a try.
 

Sokel

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Wait you just squirt it directly onto a circuit board? No downsides to that? All the videos I’ve seen of fixing coil whine on video cards and PS5s look a lot more complex from professionals.
Mine is covered with it (look at the little white bloops) :

1200as2.jpg
 

fpitas

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No guarantees, but it's cheap enough and difficult to really hurt anything.
 

fpitas

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fpitas

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Another use is gluing ribbon cables securely. In the DCX2496 a familiar problem is the connectors working loose. A tiny blob of goo at each end holds them in place forever, or until you cut it.
 

Sokel

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When we have little toroids or other parts that might be subject to vibration, they get gooped.
It's a 300mm x 100mm board,I mean lots of stuff can get shaken in transport,etc.
I would use more!
 

fpitas

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It's a 300mm x 100mm board,I mean lots of stuff can get shaken in transport,etc.
I would use more!
Well, you have to pay people to put it on, so some restraint is usual.
 

MCH

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Noises from svs subs.... @Trangbar I would appreciate if you report back any success or lack of. Thanks.
 
OP
CleanSound

CleanSound

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Drowned it in silicone. That's on top of the existing white silicone.

If this doesn't do it, then I will just have to live with it.

This is a replacement plate from SVS BTW.

1000025695.jpg
 

fpitas

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Drowned it in silicone. That's on top of the existing white silicone.

If this doesn't do it, then I will just have to live with it.

This is a replacement plate from SVS BTW.

View attachment 332050
Lol! They're going for an award from the silicone manufacturers.
 

jonfitch

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Our production guys just clean things well and squirt it on. They seem under the impression they are professionals lol.

Well let me qualify that by saying "Youtube/Influencer Professionals" then lol
 

Trangbar

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I was not as liberal as @CleanSound , but I did smother the area where I thought the sounds was coming from. My method was to remove the plate, plug it in and turn it on and then listen with a rolled up paper cone. The noise seems to be emanating from the coil that was not covered with the white silicone from SVS. I did then plug it back in to listen with my fancy paper cone, and the noise was there still, but seemed to be a lot quieter. I will give the 388 24 hours to cure, and then reassemble the sub and see what the result is.
 

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