Try using a ground loop isolator, they're relatively cheap and they did the trick for me.
So I had this issue with buzzing/interference when using speakers on my switch whilst docked. I was recommended this product https://www.amazon.co.uk/AUKEY-Ground-Isolator-Systems-Included-Black/dp/B01LYYRT7M I live in the uk so you may need to look for something similar in the relevant store. It completely removed all of the interference I was experiencing and audio when routed through this device is crystal clear. May not be what you’re looking for but almost certainly worth a look. They are cheap too the Aukey one is really high quality but I’m sure others are cheaper.
http://imgur.com/KHdolYi One end switch headphone - other line in on PC sound card - takes the switch audio into your pc sound card, then just use your pc headset for switch audio and chat. The switch app is running on Bluestacks (android emu) Switch App from playstore on said emu, or sack that off and use discord up to you. Bit in the middle is a ground loop to get rid of any background noise bought off amazon for a £5 at the weekend but they have gone up slightly since - https://www.amazon.co.uk/gp/product/B01LYYRT7M/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
EDIT: Been a few posts of users of this sub doing this I take zero credit for the idea works well tho ordered a grounding loop on Friday soon as I read about it here.
I purchased one of these ground loop noise isolated from amazon https://www.amazon.co.uk/gp/product/B01LYYRT7M , plugged that into my desktop and plugged the speakers into the isolator. The static sound is still there and constant.
Thanks for taking the time to talk to your mates about this. I've come across a few people with audio noise problems with the same motherboard so I think it must be something to do with that. Frequency isolators are those cheap, often called ground loop eliminators arent they? I was thinking of getting the one in the link. They're fairly cheap so it's probably worth a shot. Thanks for the Help
Was the ground loop isolator something like this?
https://www.amazon.co.uk/AUKEY-Ground-Isolator-Systems-Included-Black/dp/B01LYYRT7M/ref=mp_s_a_1_3