I read that the cable is not necessary but it's just something that gives more power to headphones (if used)
I tried to disconect the cable and now i have no audio. the card is recognized by windows but speakers are "empty" even if i connected the cables. The only audio source that seems to work is the digital audio but i have nothing connected there.
So i read a wrong thing or is there a way to use the card without connecting the additional 6 pin cable? i really don't like how it looks
The 6-pin cable provides clean power to the sound card, and minimizes possible interference. Please install the card as intended to avoid any possible issues. You could consider using a custom power cable for better aesthetics.
Since you have owned this card for a while now, I assume everything was working fine up until you disconnected the 6-pin power cable? Tried the usual things such as reinstalling the card and drivers, or changing PCIe slots?