Coil noise with Enermax noisetaker 470 Active PFC

Sklug · Post by **Sklug** » Sat Jul 24, 2004 9:23 am

Greetings,

I have my new silet PC setup, and using recommendations from the main site I bought an Enermax Noisetaker 470. Unfortunately, though the rest of my machine is very quiet, my Noisetaker is not quiet. The fans are inaudible, but I get a high frequency whine out of the supply that seems to vary depending on what the computer is doing, e.g. running the mouse up and down items on the start menu will make the whine modulate in reaction. It's quit loud and distracting. Any ideas? Should I return the PSU? Would another one do the same thing? The review mentioned the lack of any coil noise but that interaction with components can cause this. Anyone have any idea how to address this kind of problem?

Steve

shathal · Post by **shathal** » Sat Jul 24, 2004 3:34 pm

Certainly might want to send of an e-mail to Enermax's support about this - whether there's something in need of getting replaced or whatever.

Maybe someone up here has some more advice?

Tibors · Post by **Tibors** » Sun Jul 25, 2004 8:33 am

Well I am no expert at this, beyond what I learned reading on this site.

Searching this PSU forum for "coil noise" gives 62 matching threads. The general gist of the posts is that coil noise is caused by the combination of components in your system. So try changing something and see if it persists.

Sklug · Post by **Sklug** » Sun Jul 25, 2004 10:04 am

Yeah, apologies for not searching better before posting. I did last night and found a number of other people having the same problem. And that it perhaps has something to do with my 9800 Pro. Interestingly, after powering the system down overnight, the noise is gone, which suggests it might also have something to do with how hot the system gets (still reasonably cool here this morning).

Steve

azmo · Post by **azmo** » Sat Jul 31, 2004 5:14 am

"which suggests it might also have something to do with how hot the system gets "

I had noticed it was occuring more when the power ramped up. My hypothesis: it's contingent on inadequate fan speed in the power supply. I haven't had any coil whine since I turned it up to ~1000rpm, but that could be a coincidence. I'll try to isolate some of the factors. Unfortunately the fan is very audible at 1000rpm (the only annoying sound other than my power supply is the undecoupled seagate in idle diagnostic mode).

Sklug · Post by **Sklug** » Sat Jul 31, 2004 8:07 pm

Well, I got annoyed enough to open the thing up today. Poked around with a pencil to see if I could identify the coil or component that was making the whine. Unfortunately, it was a bust. There seems to be a lot of "glue" like material already in there from the factory, most likely to dampen these sorts of things. But as far as I could tell just using my ears, the sound seems to be coming from the transformer(s) in the middle of the unit. None of the many coils responded in the slightest to touch from the pencil eraser. And neither did the transformers. *sigh*

Just thought I'd share my lack of success.

Steve

PSK · Post by **PSK** » Tue Aug 03, 2004 7:48 am

I just thought I'd add my 2 cents. My PSU is a 300W Aopen which now has the same terrible high pitch noise described in this thread. However it only began after I installed a Seagate 80gig HDD. My original drive was a Maxtor and it was fine hooked up to the Aopen PSU.

So it might pay to look at your components as mentioned earlier, particularly your Hard drives.

This should also be of some use:

The coil noise is a result of poor grounding in the input power and/or high end graphics card with poor power filters. The PFC circuits are sensitive to poor grounding, usually using a better filtered power (UPS or line conditioner) solves the problem in areas with poorly grounded outlets. Also, Radeon 9x00 cards and FX5x00 cards from certain manufacturers don't have good power filters on the card, this results in electrical noise/feedback being sent to the PSU which gets amplified in the coils. Which graphics card are you using? If you have a good set of speakers on hand, try plugging it in to your sound card and putting the volume on high (without anything playing on your PC), you should be able to hear the noise being transmitted through those as well, the PSU isn't related to the problem.

Sklug · Post by **Sklug** » Tue Aug 03, 2004 1:03 pm

Interesting... I'm using a 200GB barracuda 7200.7 as well.

JazzJackRabbit · Post by **JazzJackRabbit** » Fri Aug 06, 2004 8:42 pm

Sklug wrote:Well, I got annoyed enough to open the thing up today. Poked around with a pencil to see if I could identify the coil or component that was making the whine. Unfortunately, it was a bust. There seems to be a lot of "glue" like material already in there from the factory, most likely to dampen these sorts of things. But as far as I could tell just using my ears, the sound seems to be coming from the transformer(s) in the middle of the unit. None of the many coils responded in the slightest to touch from the pencil eraser. And neither did the transformers. *sigh*

Just thought I'd share my lack of success.

Steve

I think you'd get more reliable results if you use microphone... it won't get you exact source of the coil whine but at least you should be able to get the general area where the sound is coming from...

gianni · Post by **gianni** » Sat Aug 07, 2004 3:37 am

Hi, I am a newbee.
I have the same trouble with my Enermax Noisetaker EG475AX(G) (active pfc at 230V AC).
The only noises I can hear in my PC are the coil noise and fan noise from the PSU.
I have just changed my Thermaltake Silent Pure Power Xaser Edition 480W APFC 110V-230V AC with an Enermax Noisetaker to suppress the last source of noise in my PC...

Now I have a PSU with wonderful cables

(MikeC, those stiffy cables are very easy to use for me: not too long, not too short and with a molex in every place I need; I spent 16 hours of cablegami with the TT PSU in a TT Xaser III; I spent 2 hours to change the PSU and to reach a better result)
Now I have no more PSU vibration

Now I have a coil noise

Now I have PSU fans with 1300 rpm idle and 1800 rpm on load

I have the same noise and 120â‚¬ no more in my pockets

luminous · Post by **luminous** » Sat Aug 07, 2004 8:11 am

Coil whine is often evident only at certain loads for the PSU. Its normally down to the exact components that you have in your machine. If you have anything that is lying around that can consume power quietly, use it. For example, an old (but quiet) HDD. Or if you are using a fan controller try altering the voltage that you are supplying your fans.

If that does not work I would RMA the PSU. Send an email to their tech support detailing the problem, and what you have done to try and work around it. The chances are they will change your PSU. If they won't help you, post on here. Then we can start a mini campaign

azmo · Post by **azmo** » Sat Aug 14, 2004 1:40 am

I replaced the seagate with a new maxtor then switched the 9700 for an x800 pro. no luck. so then I replaced the x800 with an old ati and then geforce mx. nope. unplugged the dvd writer. nope. the p4p800 SE is the only component that didn't change.

So I moved my computer 10 feet away using a wireless mouse and extra long kb/monitor cables. That helps for the low (and now almost constant) whine, but not the louder but less frequent whine which is audible from 20 feet away.

I'm going to replace it with a fan modded antec because the whoosh is at least constant, therefore easier for the brain to automatically cancel out. I emailed the delegated canadian support (and even US support) about getting an RMA but have received no response in two weeks.

luminous · Post by **luminous** » Sat Aug 14, 2004 2:36 am

If you can hear it 20 feet away I would pursue that RMA. I'm not up on the law across the pond, but we can choose where to return our faulty goods. We have the right to return the unit to the place we purchased it from.

So if you are not getting any joy from Enermax, try and get it swapped by the place you got it from.

Sklug · Post by **Sklug** » Sun Aug 15, 2004 9:58 am

Well, since RMAing the unit wasn't really an option (I opened it up.. DOH), I went ahead and got a Seasonic Super Silencer 460W A3. It's very quiet, and no whine!

Moved the Enermax to my wife's machine, and so far no whine when in her machine (though hers is not nearly as quiet in other ways as mine, so the whine may simply be masked). In any case, it quieted her machine down a lot, so I don't consider it too much of a waste.

Steve

Coil noise with Enermax noisetaker 470 Active PFC

Coil noise with Enermax noisetaker 470 Active PFC

Enermax NoiseMaker