Hi,

the link at the end of the online article links to "bequiet! Dark Power Pro 10 550W Power Supply" thread, not this one!

What I wanted to write was:

What at great review, thank you Mike!

And I also love the flow of (IMHO) relevant and interesting reviews (cases, PSUs, low noise computers, CPUs etc) instead of all those SSD reviews.

Best
Casper

So if we ignore the annoyance factor of those noises, could they indicate a short/mid/long term electrical problems?
I'm not an electrician(I just play one in minecraft), but I wonder if those noises could be coming from, for lack of a better word...'micro-sparks' on/in some components?

That noise takes energy to generate, so if that problem is resolved, could this PSU's efficiency be even higher?

There has been some discussion elsewhere on this forum suggesting it may be down to local mains supply conditions. This would explain why some people have had replacements for whining units that also whine. It would be interesting to see a fast fourier transform of both the electrical and accoustic noise produced by these units.

Many thanks for this review, as well as other recent ones. As usual, a pleasure to read.

I'm wondering whether the noise issue might be resolved if the PSU were used with other mainboards?

Great, yes, we're pushing extra hard these days to catch up. More still coming!

The whining / buzzing is not sparking of any kind. It is the mechanical aspect of an electronic resonance or oscillation in a circuit or part. When the parts were discrete (transistors, diodes, caps, coils, etc), a part swap or a redesign of the circuit would be done to tune out the oscillation. This is much harder to do now that huge chunks of PSU circuits are contained in IC chips.

in any case, I hope I have not given the impression that the second sample was bad, it's not, the buzz is really only audible from under about 1 or 1.5', and even then, at a trace level.

Good catch on the buzzing noise Mike. You are already getting hand-picked samples that are not representative of what customers get, so it's only fair to report the problem. You've given seasonic good reviews over the years, so people may get the impression it's just subtle advertising. I still want to see colorful plugs and sockets from seasonic, black-on-black is hard to see, especially inside a case.

Looks like 520 buzz/coil whine is by design. There is a poster in the power supply forum with the same issue.

viewtopic.php?p=568856#p568856

So looks like 400/460 are a better choice if you're truly noise conscious.

Hi Mike and guys,
do you know if P-460 have same buzz/whine?

Are the modular cables interchangeable with the Seasonic X series Gold power supplies?

MikeC: Any sign of a new SFX from Seasonic?

No special news on this; I think they are holding with their Gold rated models.

You're jumping to conclusions here. "By design" is hardly a fair description: No one designs in buzz into a PSU deliberately! And two instances doesn't make it an inherent part of the product, either.

It's probably best to monitor a large user base for feedback on this issue -- SPCR and other tech forums (where members have shown some concern/awareness of noise) and maybe Newegg product feedback.

Maybe I don't understand you correctly here, but there are no Gold rated SFX PSUs from Seasonic, right?

Sorry, you're right, my mistake, their Gold models are TSX, not SFX.

Hi there.

I bought a Seasonic 460-FL a few months back. And from day one it had a pitch noise audible from around 2 feet during the day. The problem is i purpose built the computer to run thru the night when i sleep and i can hear that noise even from 3 meters away in my bed.

I have a totally fanless system using a Ninja 2 and SSD. What really pisses me off, seasonic sell that unit as 0dB and it definitely is not 0dB. The problem is, which fanless power supply is totally silent?

What about hybrid PSUs that only turn on the fan past a certain load point? I've never heard a sound from my Seasonic X-560 and I'm quite certain the fan has never turned on (I don't have a dedicated GPU). I usually turn my computer off at night but I don't notice it and can sleep fine with it running ~1.5m away from me.

I have an X460 and I don't hear it. And I'm super picky about all sorts of noise from solid state and mechanical components. My fans, hard drives, and video cards are audible, but I am happy with the PSU. I think it's hit and miss with the combination of components and the power source as well.

I just got a Seasonic 400w Platinum fanless (SS-400FL2), and there is a small amount of buzzing/electrical noise when the power supply is plugged in (but computer off). However when I turn the computer on, the buzzing seems to go away, and it becomes silent. But when I turn the computer off, it starts buzzing again.

Should I return it? I'm worried that the buzzing might be a sign of some electrical problems.

http://www.amazon.com/gp/product/B003ZWQXUQ/ref=oh_details_o00_s00_i00

A very faint buzz doesn't seem like a problem. If it was really loud I would but there is no reason to assume it is faulty as it is.

There are different opinions on buzzing with Seasonix X series fanless units. I have one and have never had any problematic noise even though in my case the PSU lies with it's vented side exposed to the outside behind just a mesh. Some people have had multiple units which have buzzed and Seasonic have had mixed success with diagnosing buzzing units from MikeC's previous work. For this reason I suspect that it may not be the units themselves inherently buzzing but a combination of units and local electrical conditions. If someone has a really buzzy unit then maybe users could collaborate and meet up to compare? I had thought of pulling the earth of the power input to mine and seeing if it buzzes then!

I'm sorry, $150 is far from a "pittance" for a power supply, no matter what it does.

Would it be OK, from a cooling perspective, to use this PSU (or any other Seasonic fanless one) in a case like the Lian Li PCQ08, which normally draws fresh air from a side intake, and exhausts it behind the case?

I use such a setup in a Silverstone SG03 and it works fine. Perhaps in very hot climates at peak loads it wouldn't be as cool as it might be when installed in the recommended configuration but it is unlikely to make a huge difference.

Addendum added for findings on 3rd 520W Platinum sample.

3rd time's the charm.

"As mentioned in the review, Seasonic reports that adjustments in the BIOS of some recent motherboards eliminates electronic noise completely with many earlier production samples. The settings are:

BIOS set up to ENABLE ErP/EuP (S4~S5)
BIOS set up to DISABLE Audio Always On"

I'd love to see some feedback from users that have these BIOS options in their mobo to see how well it works.

I've never seen that in a BIOS. Can someone please explain what it means?

I'm going to guess it's for enabling onboard audio even if a discrete audio card is present. Presumably "disabled" would be to disable onboard audio if a discrete card is present during POST and "enabled" would allow you to have two sound devices active at the same time.

PMSL:

"Secondly, they have a tough time measuring or hearing this noise because it is at such a low level, and Taipei is a noisy place. I did visit Seasonic headquarters in one of my trips to Computex, and while it is not a particularly noisy building, it is in Taipei, on the Northern side, and nowhere in Taipei is very quiet"


Sorry Mike, we can't hear the noise you can hear because Taipei is loud.

Re: third unit

The effort to eliminate electrical noise makes me want to try a Seasonic PSU again - especially a passive one - as the constant buzz and whine issues are why I've been leery of them. I just have bad memories about having to replace parts, Seasonic included, because the "slight" buzz or whine has in reality been too distracting or made me uneasy. Sensitivity can suck (and tinnitus is even worse).

I'm hardly after "perfect silence" anymore (just look in my sig), but some qualities I will not have in a soundscape I have to spend 6-10 hours a day in.