WHAAAAAT!? Interesting! So that's where you've been all this time,
@Zero You must've been so excited to share this wealth of info with us. Good on Larry from HDPLEX for sending you a prototype 400W unit! You are a brave man to test that on your HDPLEX-300 like that. How did you figure out that epoxy would be the fix, is the coil whine just a result of the inductors vibrating and creating that whine?
Would you recommend this for others to do as well?
Do you have any tips to make the results the best possible?
What are any possible negative risks/dangers or long term effects of this epoxy being applied to the HDPLEX-300?
Have you applied any Epoxy to your 1080mini to see if it would reduce coil whine coming from it? I'd like to also explore this option.
So, you said you ended up recording before and after noise levels for the 300. Did you also record noise levels for the 400 in the same test situation?
Could you post those audio/video results please? I'm REALLY interested in doing this Epoxy thing to my HDPLEX-300 if it'll HALF my coil whine.
@hdplex To be perfectly honest, I only wanted the HDPLEX-400W to eliminate the coil whine I get from my 7700k/1080mini/HDPLEX-300 system. sorry Larry I guess
I'll be buying that JB Weld "ClearWeld" instead of an HDPLEX-400, I'm not really looking to jump up from my 7700k/1080 anytime soon and the HDPLEX-300 is MORE than enough for my current system. The 1080
Ti mini is tempting for higher 4K FPs at Ultra settings but I'm satisfied right now at 4K with a few dropped settings to achieve 60fps.
Coil whine is almost always inductors vibrating from the magnetic fields... the inductor what the "coil" refers to. Since the 12v coils are the only ones that are exposed, and the smaller inductors on the HDPlex are 5v inductors for the SATA (which I don't use since I have an M.2 drive), I figured I'd use the epoxy to immobilize the coils.
"Would you recommend this for others to do as well?"
If you have a 300w unit, there isn't much harm in trying and it can produce great results. The epoxy is cheap and sets fast, but I recommend in leaving the PC off at least overnight so it can cure. The epoxy is non-conductive, though it does produce some heat while curing, not enough to affect the inductor coils, but I wouldn't apply it anywhere else.
"Do you have any tips to make the results the best possible?"
Make sure to clean the coils with rubbing alcohol on a cotton cloth, dry completely, then try your best to get it to "fill in" the gaps of the coils with the epoxy. ClearWeld is pretty thin, but there might be a more thin epoxy I don't know about which achieves better penetration. Though if it is too thin it could leak to the rest of the board. For now I think ClearWeld is the most appropriate unless someone experiments and finds something better.
"What are any possible negative risks/dangers or long term effects of this epoxy being applied to the HDPLEX-300?"
Theoretically, if the vibrating of the coils eventually caused the epoxy to break loose, the rattling of the coils/epoxy could be as loud or louder than before. However, I've used JBWeld to hold some steel locknuts on my car wheels (to bolt some custom hubcaps on) and they've held up at highway speeds for years now. It's serious stuff, so I doubt it would ever deteriorate, and even if it did you could simply apply more.
"Have you applied any Epoxy to your 1080mini to see if it would reduce coil whine coming from it? I'd like to also explore this option."
I returned the 1080mini and current am using a 1080ti Founders Edition. In either case, all of the GPU's I've ever seen use 100% enclosed inductors. If they used exposed inductors, I'm confident we could epoxy them the same way and eliminate coil whine. There's no way I'm up for taking a dremel to my 1080ti to expose the coils, though. Mabne if someone has an old/broken GPU we could experiment with unmasking the inductor coils, but I'm betting the risk of damage is really high. It seems like the best way to avoid coil whine on the GPU is to have a larger PCB with more phases, which presents a challenge to us SFF folk.
A petition to ask GPU board manufacturers to use more robust, exposed inductors like the HDPlex 400w would solve the issue as well, but good luck getting them to listen and spend a little extra...
"So, you said you ended up recording before and after noise levels for the 300. Did you also record noise levels for the 400 in the same test situation?
Could you post those audio/video results please?"
I did not record the 400w because my phone honestly would not have picked up any noise over the rest of the system.
I am camera-shy but if you message me directly I'll send you the 300w before/after videos. I don't want to post my voice/bedroom in public
"
To be perfectly honest, I only wanted the HDPLEX-400W to eliminate the coil whine I get from my 7700k/1080mini/HDPLEX-300system."
To be clear, my 300w had *loud* coil whine, as in audible from the next room over while benchmarking, and the epoxy took it down to quiet but audible from sitting distance. The 400w on the other hand is completely inaudible at sitting distance, even with an overclocked full load. There's no harm trying the epoxy on the 300w first, as you might get it to be as quiet or quieter than your 1080mini. Lastly, consider that the HDPlex 300w might be "straining" a bit to deliver power at full load, which may or may not contribute to the whine of the GPU. For example if the HDPlex is operating near peak and there are anomalies like voltage ripple, that could cause the inductors/VRMs on the GPU to work harder to compensate. The 400w PSU would spend more time below peak where it can operate more efficiently and accurately.
For anyone without a 300w HDPlex, getting the 400w is looking like a no-brainer; about the same price, about a centimeter longer but still fits the HDPlex fine, and this prototype seems to be handling my overclocked 1080ti while barely heating up and keeping dead silent.
