Grounding and headphones, how to make clear sound from headphones?

Question

Iron

Good afternoon!
There are expensive headphones with bells and whistles, and the fact is that the headphone connector via USB, when connected to the back of the PC (2.0), there is noise in them, barely noticeable, but annoying in complete silence, nothing changes when connected via 3.0.
The PC is not grounded
I asked the sellers and advised me to buy a USB-HUB, I didn’t understand, because usb-hubs are just expanders, but they told me that they could somehow remove electrical noise, etc!
Everything is ok with firewood, I checked on other computers where there is no grounding at all, there is generally tin, well, in fact, in the store itself, where there was grounding, not a drop of noise and the purest studio sound!
The question is, is there really such usb-hubs, and if so, can you give an example?
Is there any way to ground the pc?
I'm looking for more electronic things that can work as a filter SOCKET-FILTER-PC.

Answer 1

I had a lot of noise from the speakers and this thing helped me - apc-p1-rs (google it) - the background became barely audible.
Perhaps it will help you, or maybe not - there are a lot of different interferences in the network and not all of them are easy to remove.

Answer 2

The noise seems to be 50 Hz. You need to ground the PC case, you can to the battery, but this is a bad option. In apartment buildings, the nearest ground point is a metal shield with electric meters in the entrance, you can run a wire. If you have cable TV, you can ground it from an external shielding braid.