Some "audiophile products actually work
>be me
>buy fairly high end subwoofer
>has a giant toroidal transformer
>transformer randomly has an audible hum when just plugged into wall outlet
>find out its because my power grid is absolute shit and leaks DC onto the AC lines and this causes some toroidal transformers to buzz loudly
>take a chance and buy pic related for $150
>it actually fucking works
I know its overpriced as fuck for a plastic dongle with some capacitors n shit, but I ain't taking a chance to make my own when dealing with 120v power and risk blowing up my sub or house
Fortunately its very well made and completely unobtrusive like some other options