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

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.