Severe short term audio distortion when watching Netflix

Hi all , I can't find a reason for this anywhere - so posting as widely as possible

My Setup

New Win 10 PC with Matrix Element H USB card - Sablon 2020 cable to May KTE DAC - handmade Silver XLR's to Hegel H390 to Dynaudio Heritage Specials

For the last 12 nights, while watching Netflix or Youtube - the audio is swamped by severe high pitched distortion for 3-4 seconds , then all returns to normal

This only happens once per night - between 7 -10PM. Only once, never during the day and only for 3-4 seconds - all was good for more than the last 12 months with this current setup

I have contacted my internet provider - all is good from their end - have checked with a speed test as soon as distortion starts and speed is normal

I have replaced the Ethernet cable

I have uninstalled and reinstalled the Holo Audio driver for my MAY KTE DAC - on a suggestion from Microsoft Support

I have rebooted  PC several times and switched off May DAC and unplugged power cord for 30 seconds

Any ideas or suggestions appreciated




I've been shown how to access real time process monitoring from the task bar - I'll bring up that window at 7pm tonight and see if anything spikes during distortion.

What sort of interference do you mean  - I live in a ground floor apartment in a group of 5 - as far as I'm aware - my neighbours all use laptops - don't know if that info is of any use

It's the fact that the duration of the distortion is always 3-4 seconds only  - not longer , not shorter and only once per night - just at different times during the 3 hour timeframe

If it was interference from outside - why always the same length?, and why only once?

The 3 second of distortion on it's own is no big deal from my perspective - just don't want it to be slowly frying my speakers - even though I recognize it straight away and immediately turn the volume down - it may happen when I'm out of the room

Do you live in a single family home or multi-unit building?  Does someone in your residence or a neighbor return home during that time window and switch on some device, like an air conditioner or something that might be drawing a heavy load for a couple minutes and possibly interfering with your power?