Class D amp and SMSP coil whine?

[CleanSound]

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]

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

 

[CleanSound]

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

Yup, I ordered this one. Let's see how it works out.

Amazon.com

 

[DVDdoug]

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

 

[fpitas]

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

 

[jonfitch]

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]

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]

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]

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) :

 

[fpitas]

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

 

[fpitas]

Mine is covered with it (look at the little white bloops) :

View attachment 332015

When we have little toroids or other parts that might be subject to vibration, they get gooped.

 

[fpitas]

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]

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]

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]

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

 

[Trangbar]

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

Will do. The silicone should arrive in a few days and I will take some pictures as I do it.

 

[CleanSound]

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.

 

[fpitas]

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]

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]

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.