Buzzing sounds / noise with HDMI, analog out and USB DAC

Hello there,

I’ve recently purchased a Vero 4k+ and after reinstalling osmc (had some issues out of the box) it now works fine.
I have some issues with audio (my initial setup was Vero attached to TV with HDMI and 2.0 hifi stereo system attached to TV with RCA cable); in particular I was hearing some timed ticks and strange sounds during playback. I tried many options in the audio section (passthrough, changing sampling rate…) but had no luck.
I then decided to try our the analog output, directly connecting it to my stereo system with 3,5 mm to RCA cable… had the same issues.
I then decided to try my USB DAC (AudioQuest Dragonfly RED), connected it to usb, aformentioned 3,5 mm to RCA cable running to my stereo system, rebooted. Setup the DAC as Audio output decive (tried both with analog and spdif setting), limited sampling rate to 96 kHz (max supported by DAC).
Issue now is that I hear a very high pitched noise, during any tipe of sound output by the Vero (playback and menus)…

Got any idea on how to solve this? Maybe some software tweaks to better use the DAC?

Note that my stereo system works perfectly fine with other direclty attached sources (CD players, aux) and with the TV itself (through the same RCA cable) when playing sat TV or DVDs.

Lets look at HDMI first, do you get the ‘timed ticks and strange sounds’ through the TV speakers with the HiFi disconnected?

How about with headphones from the TV?

Just tried: with the HiFi disconnected and sound from TV built-in speakers I can’t hear anything strange. When I try headphones in the TV headphone jack I also can not hear anything strange.
However, trying connecting the HiFi system to the TV headphone jack (3,5 mm to RCA cable) results in the usual interferences.

This may lead to think it is the stereo system that is suffering some problems, but with the same 3,5 mm to RCA cable other sources sound perfectly fine (like my phone or PC).

Seems like some sort of earth loop. Not sure what to suggest.

Ok I have played around a bit and discovered it is the powerline. I have a tplink powerline with wifi access (no ac plug passthrough) and it was sitting in a wall socket alone. But next to it was the TV. As soon as I detached the powerline from the wall socket the sound disappeared. I am now trying to figure out what to do.

Any suggestion from others’ experiences with powerlines?

Can you run it on a different socket?