I've recently constructed a new machine at the heart of which is a Seasonic x-760; a buzzing, obnoxious bastard whose vendor-issued replacement is just as bad if not worse. At a distance of up to five or so feet the buzzing sound, which fluctuates with system load, is audible and to my ears particularly trying. In an attempt to silence it or at least pinpoint the cause I've tried all the various UEFI-level band-aid fixes such as disabling EIST and the various C-states--not that I would want a PSU which would not allow me to comfortably use those power saving options. The frequency of the buzzing changed with the CPU drawing its load voltage at all times, but was not a difference I would call any more or less acceptable. Removing the video card outright and unplugging the various drives in the machine had no appreciable bearing on the sound. Unless I find a silver bullet, replacement seems inevitable.

When selecting parts for the build my second choice was a Corsair AX of some wattage as it's one of the only other fully-modular PSUs that was both well reputed and, more importantly, available from the vendor (NCIX). I would like to give one a shot, but as a derivative of a Seasonic would it even be reasonable to expect any different? And if not a Corsair, what then? My options seems limited with most of the other usual suspects suggested here (Kingwin, Enermax, Super Flower, etc) being only available in Canada at Newegg.ca, which I'd like to avoid courtesy of a bad RMA experience, or not at all.

Sometimes PSU's just don't play well with certain motherboards (or vice versa). It could be the x-760 works great everywhere but for this mobo or it could be that it's just a sucky PSU. Happen to have another PC (with a different mobo) you can try this PSU in?

As far as replacements go, what's your build (CPU, GPU, etc)?

I could scavenge another mobo as a test machine, but I'm not sure to what end. Since I've already tested two x-760s I'm more inclined to believe that the problem is the PSU itself or the result of a mismatch between the PSU and other components. If I discovered it wasn't, then I'd not really be any closer to solving the problem unless I replaced the motherboard which has caused me no grief (knock on wood). Short of maybe a root canal there isn't much I'd more like to avoid than swapping out that thing, anyway. If there were some evidence that exchanging it for another of the same kind could at least plausibly solve the problem I'd definitely reconsider--I like this thing.

As for the build, the important bits:

Mobo: Asus P8Z77-v Pro
CPU: i7 3770k (noise is produced both at stock and at my not-insane overclock, with and without the power saving options)
GPU: Asus 670 (likely irrelevant; buzz persists with the thing removed using onboard video)

The remainder are an NH-D14 and its stock fans, two Noctua P14s, two Noctua P12s, and an Intel 520 SSD. Nothing else has yet been put into the machine.

So, unless you overvolt, it'll be <300W stress load, probably 200-250W gaming. Your RMA experiences and lack of other options is pretty daunting. (If it was available, I'd opt for the Kingwin LZP-550.)

You could try another Seasonic at a different wattage rating or different model series... The 760 was overkill, anyway. The x-560 would be a good fit...the fan still won't turn on for your load. The G 550 might work, but I haven't seen a decent review for noise, yet. The fan profile looks aggressive. Heck, you could put an x-400 or x-440 fanless in there. You could try out one of the just introduced (and yet to be reviewed) fanless SS-520FL platinums or it's semi-passive sister the SS-660XP.

I hadn't really considered trying another x-series of a lower wattage; I subconsciously assumed that they would be similar enough that if one was a metallic beehive another then would just as likely be, too. But given how much I like the thing otherwise, it's probably worth a go.

The 760 was overkill. When pricematched it was cheaper than the x-660 and only marginally more expensive than the x-560, so it seemed the obvious choice. Having room to maneuver into SLI and a larger array of drives was part of the attraction, but I imagine the x-560 would still suffice to that extent (I wouldn't be so keen to downgrade to the x-660 at a higher price than the x-760). I'll give it a shot and post an update, ideally positive, when it's done.

As for the rest, the new Seasonics sound pretty attractive. Especially the new fanless 520w. If any of them were currently available at NCIX I'd jump at the chance to try one. Since they stock most of Seasonic's other PSUs I'd even consider waiting until they appear, but with a closing return/replacement window I don't think I can. Should the x-560 give me the same headache one might be available to try during its return trip.

good luck!

Is it possible to put some 100% silicone on the coils? Not sure if that trick still works, but it is something we used to do in the old days of SPCR, especially on motherboards.

Might mess up his warranty/RMA option.

He has already RMA'd it once and same problem, so I don't see what there is to lose. The question is "can it be done and will it help reduce the noise?" and not "what are the warranty implications?"

What can he lose? The ability to get a free replacement. I'm all for modding if you don't care about the warranty.

I will say this again. He has already RMA'ed the X-760 PSU and the replacement acted just like the original. It seems unlikely (unless Seasonic changes the design of the X-760 before he does another RMA) that the buzzing will stop with his current PC setup, unless he changes something. Therefore, additional RMA's of the PSU are not going to do any good.

Whatever you think of Seasonic PSU's in terms of noise, buzzing, etc, it is very unlikely that the X-760 will fail within 5 years, once it is known to be working and not to be DOA. So voiding the warranty is not a big concern IMO.

In the early days of SPCR, almost all of us had to open our PSU's to change the fan, or something. People are spoiled these days.

I think you missed the bit where his RMA allows him to pick a different model. Hence the discussion of what different model to pick. Will it resolve the problem? Maybe. It could be the different components in the 560W are far enough away in value to not resonate in conjunction with his Asus mobo.

I still don't quite see that in his posts, but I guess if he RMA's with NewEgg (instead of Seasonic) they may allow that. If so, the X-660 is a no brainer.

One other thing I would try is plugging directly into wall socket, bypassing the UPS (assuming one is being used). Some UPS's are not compatible with the newer Seasonic's.

Well, better late than never...

Simply, the x-560 exhibited much less buzz than the x-760. Whereas the x-760 was audible from a few feet the x-560 could only be heard from a fraction of that; maybe one or two. Certainly quiet enough that it couldn't be heard during use.

So I chose to keep it.

As I finished off the build and swung it into use, however, a couple joyous irritants popped up.

The first was that with both fans attached my NH-D14 would produce an unusually loud harmonic/hum. Much louder than any of the fans in the machine, and certainly the two attached to it. I tried all sorts of permutations of different fan resistors and connectors, reseated the fans, ensured the rubber(?) fan buffers were firmly pressed against the fins of the heatsink, etc, and could simply not eliminate the noise without removing one of its two fans.

The other was that under heavy load, typically newer games demanding of both CPU/GPU, the machine would very gradually (perhaps over 5-10 minutes) produce a similar, though different, hum which would then fade after the machine had returned to idle for 10-15 minutes. Given the delayed reaction I couldn't assume it was any type of coil whine I'd ever heard of and eliminated the next most likely culprit of a misbehaving GPU fan by manually setting its speed to its lowest and putting it to its paces. With the PSU's fan being the only other dynamically controlled I couldn't rule it, or even some other component of the PSU, out as the cause and didn't want to render some judgment of the thing here before resolving it.

I left the second issue on the backburner while I dealt with Noctua to hopefully silence their beast. After waiting quite some time for a replacement fan to be shipped from Austria I found that the center fan was not to be blamed and so began another long wait for an exterior fan replacement. It eventually arrived and made no difference either. Huzzah!

Mostly fed up and under the impression that Noctua would be reluctant to swap the aluminum I left the second fan detached and just ignored or avoided the issue of the gradual hum. Until a few weeks ago. Without any action of my own or even any movement of the machine the hum simply wasn't being produced anymore. Nothing. It was just one day gone. It, thankfully, hasn't returned since. I've taken a few stabs at its cause and spontaneous resolution, such as some component or capacitor resonating only beyond a certain temperature which eventually settled, but it's all guesswork. I realize it's off-topic but if someone has any insight I'd love to know what the hell might have happened, and if it might return, and my Google-fu's gotten me nowhere. I'm still building up the courage to see if the issues were related and reattach the second fan to the heatsink without awakening the beast.

Ultimately I think the correlation between popping in the x-560 and noticing the aforementioned was simply coincidental and that the PSU is fine and at least under my conditions produces less buzz than the x-760. So there you have it.

And to quickly address the above: Steve hit it on the nose. I might have considered tinkering with the PSU itself but not within its return/replacement window. I also did indeed try the original x-760 with and without various surge protectors (I am a philistine with no UPS) and at different outlets throughout my home. No dice.

Perhaps this info from Seasonic might be of help if you have not already seen it. Have a read of this thread from this point on:
viewtopic.php?p=573354#p573354

Basically there are some motherboard settings identified as causing buzzing/whining and its because it puts the PSU out of what it's really designed to do in respect to recent legislation. That thread might be about the G series but it also applies to X and Platinum series models too.

Maybe it isn't the same problem for you but might be worth a look.

Glad the x-560 helped reduce the noise. Please note the Seasonic Rep popped on the boardsa little while ago and talked about PSUs meeting ErP2013 standards may cause the problem and how if your mobo bios isn't set correctly, or if the mobo isn't compliant, it can cause/accentuate the buzz.

As far as the mystery hum goes - if changing the Gfx card's fan profile got rid of it, then it implies there's a resonant point somewhere in the fan rpm profile. Call me Sherlock You could try manually stepping the rpm until you hear it...and then use a program like MSI's Afterburner to create a custom profile that doesn't go there.

cpu cooler: how are your temps with just one fan?

I hadn't heard of that issue with the Seasonics. Interesting. While I'm nearly positive I left all power saving options (EIST, ACPI states, etc) enabled from the get-go, I wonder if one of the P8Z77 UEFI/BIOS updates I've installed over the months changed something. I didn't scrutinize them that closely. Will look into it. Thanks.

With regards to the video card: It's elementary, Watson! I eliminated the video card as the offender by manually stalling its fan at its lowest easily-configurable speed (i.e., the sound persisted under those conditions). I probably failed to write that clearly. As for the CPU whose cooler I'd very much like to restore to its buxom double-fanned glory: I'm not entirely comfortable running something particularly strenuous such as prime95 or F@H to test it at its absolute practical limits, but under my typical demanding conditions (long encodes/gaming) it hovers around 60. Cores reported 25-33 while typing this at idle.

60C is fine. Idle temps are fine.