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Warning! Antec SP 2.0 450W produces high-pitched tone

Posted: Tue Jul 18, 2006 10:13 am
by mg2plus
This is a followup on an earlier post which can be found at ... highlight=

Anyway, I got a third Antec SP 2.0 450W with PFC, and this one also produces a high pitched tone (I think that's called 'coil whine'). This is a second one in a row having the same fault, and I think that whole line is faulty.

Also, there is a possibility that models without PFC don't suffer from the same problem (the first SP2.0 that I got was without PFC). Also, you may not have this problem if your machine has different power requirements (mine draws around 115W).

So be warned! Antec SP 2.0 450W with PFC has a serious problem.

Posted: Tue Jul 18, 2006 2:25 pm
by nici
Most likely it just doesn´t like some of your components, i´ve only tested a SPII 450W briefly with my sig setup and it definatley did not whine, but i only had it plugged in for about ten minutes or so.

edit: It has PFC.

Posted: Tue Jul 18, 2006 4:02 pm
by acyf
I don't know what's wrong with yours. I got a SP450 that comes along with Sonata II and it's quiet like hell. Where did you record the sound? At the back of the PSU or what?

Posted: Tue Jul 18, 2006 4:39 pm
by jaganath
I got a third Antec SP 2.0 450W with PFC, and this one also produces a high pitched tone (I think that's called 'coil whine'). This is a second one in a row having the same fault, and I think that whole line is faulty.
Are you absolutely sure the sound is coming from the PSU? I had a similar problem to you and I eventually discovered it was the inductors in the VRM on the motherboard that were making the high-pitched sound. PSU's with active PFC don't usually make that noise, as aPFC is done using microelectronics, as opposed to the large inductor coils required for passive PFC which can vibrate at harmonics of the DC frequency.

Posted: Tue Jul 18, 2006 4:48 pm
by Smith3000
I have recently installed one of these and noticed a high pitch noise then too. For me though i cant hear it when the computer is in place, only from the the back, but then i only have a stock cpu cooler and 2 hdd so the rest of it is noiser. My system is an old Athlon XP, i dont imagine it draws much power. I dont know if it has PFC?

Its a shame though that there has been a number of reported issues regarding antec, there products always look pretty good. Well at least i am happy with my antec case. Given the choice of products i can get though, the antec is definatly better than a cheap PSU.

Posted: Tue Jul 18, 2006 9:38 pm
by burebista
Hmm, I guess that something is wrong with latest batch(es) of SP 2.0. I just talk with one of our Antec reseller and in last weeks they have a lot of problems with SP 2.0. Something is wrong in their PFC circuit.

Posted: Tue Jul 18, 2006 11:37 pm
by mg2plus
Here is an update on situation.

While I was waiting for second and third SP2.0, I had two replacement PSUs, one form MS and another from Asus. Neither of them made any distinctive tone.

Also, I'm pretty sure that the sound comes from PSU, but I will unscrew it and listen again just to be sure, and post my findings here.

My motherboard is ASUS A8N-E. Perhaps SP2.0 and A8N-E don't go together well?

I noticed that the tone that SP2.0 makes changes frequency (I think that the frequency is corelated with PSU tempereture). After about 5 minutes it goes quite high, probably near the end of my audible range, so I can not hear the tone from 1 meter away. But if I listen from about 20cm distance, I can still hear the very high pitched tone.

At this moment I'm actually considering keeping the SP2.0, as it is very silent otherwise, except for the first few minutes. But I rarely shut down my PC, so it doesn't matter to me.

Posted: Thu Jul 20, 2006 1:03 pm
by mattek
I got the same problem!

Really high pitch coil whine on my Sonata II. It's been fine for months and just now recently the noise started. To further annoy me the system wont boot. Argh!


Posted: Fri Jul 21, 2006 4:25 pm
by vitaminc
I got the same problem with SP2.0, 500Watt. SP2.0 was quite at first, but after a few weeks, it starts to moan like a b1tch. It's not a high pitch, but its some sort of vibrational noise or something, and its louder than my Seagate Cheetah RAID array. Replaced it with Seasonic 380W and its been quite thereafter.

Yes, I put my ears right next to the PSU and made sure its making that sound.

Posted: Sat Jul 22, 2006 2:20 am
by jaganath
Yet another dodgy Antec PSU?

Posted: Mon Jul 24, 2006 11:02 pm
by fyleow
I can confirm this problem with the Smart Power 500watt as well. The noise disappeared after I switched back to my old Coolermaster. There was no problem with the NeoHE I used for a short time either, only the smart power had a high pitched noise.

Posted: Wed Aug 02, 2006 2:09 am
by mg2plus
Sorry for taking so long to reply, but I was busy and couldn't do it earlier.

I took SP-450P out of the case to confirm that sound comes from it, and it indeed does. Audacity shows that the pitch is 10700 Hz but it varies for about 500 Hz. Intensity also varies with time and it is corelated with pitch, when pitch hits 10800 Hz the whine is loudest and very annoying. This happens every 5 minutes, and stays that way for some time.

So I opened a trouble ticket at Antec, and explained the whole situation. They said that they 'have not had any issue with them', and said that I should return the PSU, preferably directly to them.

Unfortunately, I found out that sending the PSU to Antec would cost me too much, and decided instead to return it to my local reseller, for the third time.

So I'm now waiting for my fourth SmartPower 450. I hope that this time it will go well. When I get it I will create another post here.

By the way, I got a replacement PSU from my reseller, it's ASUS again, and it is fairly quiet and doesn't whine.

Posted: Wed Aug 02, 2006 2:44 am
by burebista
mg2plus wrote: So I opened a trouble ticket at Antec, and explained the whole situation. They said that they 'have not had any issue with them', and said that I should return the PSU, preferably directly to them...
Hmm, I spoke again with one of our Antec resellers and he told me that Antec confirmed to his boss that they have problems with SP 2.0, but Antec didn't say a word about the nature of problem.
All I know is that 50% of their SP 2.0 sales are back in warranty, and 95% of them have PFC circuit broke (a diode).

Posted: Wed Aug 02, 2006 5:20 am
by jaganath
I got a replacement PSU from my reseller, it's ASUS again, and it is fairly quiet and doesn't whine.

Do you mean Antec? AFAIAA Asus don't make PSU's.

Posted: Wed Aug 02, 2006 7:15 am
by burebista
jaganath wrote:Do you mean Antec? AFAIAA Asus don't make PSU's.
Correct, they don't make PSU's they put an ASUS label on Enhance units... ;)

Posted: Fri Aug 11, 2006 6:12 pm
by tchicago
I've just got a replacement of my SmaptPower 2.0 350W power supply from Circuit City, and apparently it exposes the same problem as the one I've returned to the store. Basically, yes it makes the high-pitched noise.

However, when tested with the load simulators, there is no noise. Also if I disconnect the hard drives, the noise disappears too. (Obviously I've verified that the noise comes from the power supply). Also, the noise is a lot louder when the hard drives are spinning up after turning the power on.

Being familiar with the electronics, I'm able surely tell why there is such a problem. This noise comes either from the PSU's invertor transformer, or from the induction coils at the output.

Here is what happens. To rotate the disk, the hard drive consumes the power in pulses, multiple pulses per disk spin cycle. Those pulses cause the short periodic power consumption (current) spikes , and if there is a flaw in the PSU design, the inductors (transformer and other coils) will produce the sound at the frequency of those current spikes. The most obvous reason for this could be the manufacturer's desire to save on the output capacitors, so they've put a lower capacity elements. The output capacitors are meant to compensate those current spikes.

If someone has contacts with ANTEC, please forward this information to them, but I think they already know it.

I'm taking my SP350 back to the store tomorrow.

Posted: Mon Sep 11, 2006 11:21 pm
by RaptorZX3
i now get this noise when i boot-up my computer, it goes on for a few minutes and it stops.

it began well....maybe a week ago. and i have this computer since beginning of Feb.2006. i noticed that my computer makes a small noise...i thought it was my hard-disk, but i think it's my PSU, dunno....

i mostly always listen to web radio (and a big ol' 70's Rotel radio playing rock songs behind me), even when playing a game (turning off in-game musics).

edit: the sound at start is more like a "rumble" that stops after a short while, but there's still a small noise coming from the PSU fans (i took off the slot doors of my case on the front and checked if the sound come from the PSU fans).

Posted: Tue Sep 12, 2006 8:23 pm
by StrongSilentType
mg2plus wrote:So I opened a trouble ticket at Antec, and explained the whole situation. They said that they 'have not had any issue with them', and said that I should return the PSU, preferably directly to them.
When I returned the Antec SP2 PSU I got (it was making the high-pitched noise and can't boot the computer), and I asked had anyone else experience this -- you can guess what the answer was.

Edit: I described the problem I got here:

The culprit is bad capacitors

Posted: Wed Sep 13, 2006 7:40 pm
by bitpoh
I have a Antec Overture II case that came with a TruePower PSU, which started to squeel loudly (even when the computer is OFF) after 8 months of very infrequent use (computer was probably turned on for less than 10 hours per month average).

Since I already voided the warranty when I modified the fan in the PSU immediately after I got the case, I was SOL in terms of getting a warranty replacement. Opened up the PSU to try to figure out what's wrong and noticed a couple of bulging and leaking capacitors. Did a google search and lo and behold, I am not the only person with this problem. Check out the following forum threads at

I thought that only motherboards have been plagued by bad capacitor problems. But I guess PSUs are suffering from them too.

Posted: Wed Sep 13, 2006 10:51 pm
by StrongSilentType
Interesting info.

I know the motherboard makers were not the only ones using bad capacitors, but when they found out about the capacitors going bad a few years ago, I thought everyone had stop using them.

Why is Antec using them now :? Are they the same brand/manufacturer?

I think my replacement PSU from Antec is not going last long :|

Posted: Thu Sep 14, 2006 1:02 am
by RaptorZX3
IF my PSU is going to die someday, i'll try to ask the store who made my computer (i have a 3-years warranty) if i can choose another power supply they have in stock...

problem: they suck with good, reliable and silent power supplies (enermax, thermaltake....companies i never heard good things about silent PSUs yet)

Posted: Thu Sep 14, 2006 6:31 am
by bitpoh
I am stuck with a perfectly good looking Overture II case without a PSU because Antec uses a proprietary ATX PSU for the Overture II. I guess it's no surprising that they want $80 for a replacement PSU, which essentially is the price of a new Overture II altogether. :(

Posted: Wed Oct 04, 2006 4:04 pm
by RaptorZX3
well up until now my computer still boot-up without any problem, i can hear a slight noise, sometimes, coming from behind my computer, but i don't think it's a "i'll explode soon!" sound.

maybe i have a SP450W 2.0 without that "PFC"?

Posted: Sun Dec 10, 2006 11:35 am
by StrongSilentType
Small update on my replaced Antec SmartPower2 PSU. It's been about 7 months since the RMA, and it's making a high pitch electrical noise with the computer off again :|

I'm not going to waste time and money to RMA it again ... probably just get a SeaSonic.

Posted: Sun Dec 10, 2006 1:31 pm
by RaptorZX3
i don't have any problem up until now (11 months now), it's not doing a high-pitched noise when the computer is off (but the switch is still at ON on the PSU)

but of course when i close the computer, i also switch the power on the PSU at OFF, my monitor and my power bar too. (when i switch the power OFF on the computer PSU, i always wait a bit, there's a green LED on my motherboard that turn off when you turn OFF the power on the PSU, and when it closes, it do a small noise, i really think it's a normal noise)

Posted: Fri Dec 22, 2006 2:14 pm
by computergeek22
didn't want to bring up an old thread but wanted to mention that my sp-500 has the same high pitched coil whine. bought my psu 9 months ago. Not happy with antec...

Posted: Fri Dec 22, 2006 3:03 pm
by RaptorZX3
well i think i can hear it now, but it's not that loud

i don't hear it often since i generally have music playing on my computer.