High-pitched noise when connecting left half of UHK 80 to USB-C for charging

I just received my UHK 80 today. It’s the version with batteries.

When I connect the left half to my Mac via USB-C while the battery is around 50% charged, there is a high-pitched noise - I guess it happens when charging the battery.

It’s not that loud, but loud enough that I cannot work while it is connected.

I couldn’t find that particular issue mentioned in the forums.

Reducing the LED brightness doesn’t help.

If I use the bridge cable and load the battery through the right half instead, I also hear a high pitched noise from the left half, but it’s not as loud.

If this cannot be fixed in firmware, I’ll have to return the keyboard and get back to my UHK 60…

Is anyone else seeing this issue?

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Update: it does seem to be related to LED brightness. The sound is pretty much gone while the USB-C cable is connected when I set the brightness of the LED in UHK Agent to 30 or lower or when the LEDs turn off.

Setting LED brightness to something like 127 while the USB-C cable is connected to the left half is enough to cause the high-pitched noise. Remove the cable and the noise is gone.

I used a spetrum analyzer app on my iPhone. It tells me the sound has a peak at 8140 Hz:

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It’s discussed all over the forum.

Makes noise. Uhk60 did too. 80 can be quite loud alright.

I just connected my UHK 60. The LED brightness is at 255. The spectrum analyzer does also pick up some noise, but it’s much, much less loud!

This is a really a different problem and only happens this pronounced when connecting a USB-C cable to the left half.

I’ve two UHK60s, the red LED ones, they can be quite loud but I agree not as loud.

Did you try to connect a USB-C cable to the left half while the LED brightness is at least 50%?

I hear it loudest when putting my left ear next to the “G” key.

Here’s another thing I found out:

Connecting the left half to the right half using the bridge cable also makes the loud high-pitched noise immediately appear despite no change in LED brightness.

Steps to reproduce:

  • Use left half standalone: disconnect from USB-C and also don’t connect to the right half
  • Connect right half to USB-C
  • Set LED brightness to 255 for both USB-powered and battery-powered
    → I don’t really hear noise from the left half unless I get really close
  • Now connect the left half to the right half using the bridge cable
  • As soon as you connect the two halves, there is immediately a relatively loud high-pitched sound
  • Disconnect the halves and the noise is immediately gone, despite having the same LED brightness

So this must be more than just the LED brightness.

I hope this can be fixed in software. It’s unbearably loud and headache-inducing.

Thanks for elaborating! I’m working on a solution and will keep you updated.

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i just found that on my UHK60, di you know about a fix?

I must admit I am learning that age has its advantages. :blush:

I have never noticed any high-pitched sounds from my UHKs.

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i cant wait to finally get “old people hearing” despite being way in my 30s, it has yet to settle it.

i played around a bit and the pitch seems to change when toggling layers so i wonder if it is directly correlated to the layers or what i rather believe, the LEDs. but i dont know if its a diode or something. when i get my new keycaps in and ill take stuff apart, maybe i can find out what part is being a noisy little thing.

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I’m old AF too. I’m in my mid 40’s, but TBH, I lost huge chunks of my range a long time ago. I just posted this in another thread a little bit ago:

In my mid forties. So not sure on how pitched it will be.

With leds above 40 there is an audible whine. At max value it is loud and I can tolerate for five minutes max.

Occasionally the left side will emit a shrieking noise (yes is the appropriate word). This might only happen once every day or two but Christ it is loud. Seems to involve the usb cable to the left side.

I have two UHK60s. Both emit a noise. One is significantly worse than the other. I have found over the years that varying the output levels changes the tone and lower is not always quieter. The UHK80 is significantly louder than my louder UHK60.

Strangely though it does not seem LED related on the UHK80. If I set the LEDs to highest and have bridge and usb cable in use then the noise is there. Disconnect the usb cable and the LEDs are still at full but no noise.

interesting. I can only report from my uhk60v2 afaik. and turning LEDs off does the trick which is kinda sad. ill report back when I opened it up and try find out which part does the noise and go from there. I think with some soldering or replacing a part should fix it.

-e-

in the mean time: is there a way to set a hotkey to toggle led brightness on / off on fn layer? would be nice in the mean time to toggle it off when the headphones are off

<humor flavour=“dry”>I’m in my mid 50s. So just wait another 1 or 2 decades and the noise will go away.</humor>

(Let’s hope the UHK crew can find a solution sooner!)

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so found that the noise is there even when the LEDs are turned off so I made a little investigation:

I cant upload the video but there it is, seemingly it stems from the Cluster behind the display

to give credit, man the pub is crisp. im very impressed. very good work!

sadly it seems that there isn’t much in the way of resoldering, wich means there is the good old way of making stuff less noise: physical stuff.

lets see if I can simply make it hush with putting stuff on top of that cluster.

-e-

I want to say that I have improved it but I don’t think its but much if any.

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okay last little update from my side: my little adventure made it pretty much inaudible (for me) when the backlight is off. it has to be perfectly silent and I have to listen for it to hear it when the LEDs are off.

and with the open headphones its also improved.

IF im correct and from where the noise is coming, basically the other side between 3-w-e AND the components in that area are what I think they are then there really isn’t any fix in the firmware. I could be wrong and I hope I am because I want this to be 100% fixed because its really annoying but if its simply voltage through components then the only fix is in an updated pcb design for that circuit.

@mlac if you can speak on that, please do so and if there is anything the bunch of us who are blessed / cursed with dog like hearing can do to make it go away I think all of us very much appreciate it!

in the mean time I think our best bet is to add some foam and live with it. im going to see if there is something else to use that “more high pitch absorbent” whatever that means.

So what frequency exactly are we talking about?

I used to be in the dog hearing camp too just a decade ago, but have no problem with uhk80 (preproduction units).

edit: i mean, clearly we cant be talking about just 8khz - my hearing hasnt gone that bad by far yet.

Wow, that’s pretty old for a spider.:disguised_face::wink:

…aaaannnd now I’ve got the lyrics to Frank Zappa’s “Spider of Destiny” stuck in my head.

Do you know if there’s any difference between my UHK80 and the units being sold now?