Hello, how can i combine headphone AND spdif output ?
when teamspeak problem will be corrected ?
 
i was with asus xense ( = essence ) and i'm not happy with this 2 problems

My suggestion is that you contact EVGA tech support directly. 

d3de58
how to ?

https://www.evga.com/about/contactus/
 

d3de58
Hello, how can i combine headphone AND spdif output ?
when teamspeak problem will be corrected ?
 
i was with asus xense ( = essence ) and i'm not happy with this 2 problems

So, let's start with the first question.  Essentially, you can't.  The Speakers (which includes both the RCA out and Headphone Out) are considered one device by the OS, and the S/PDIF is considered a second device.  In order to use one, the other must necessarily be turned off. 
 
Now, that doesn't stop you from trying different things.  For example, an Astro MixAmp could be run through the NU Audio S/PDIF and you could connect your headphones.  But that's not really ideal, and doesn't really utilize the strengths of the NU Audio or NU Audio Pro cards.
 
Regarding the Teamspeak issue:  I am aware the Nahimic can reproduce the issue.  They are returning from their holiday break next week, I believe, so I can provide a better update then.

d3de58
why Asus do it on Essence audio cards ? i can use both audio output without anyproblems

Why does Asus? I don't know. This isn't an Asus website.

Why doesn't EVGA? I can only speculate: having longer trace length in circuit increases electrical interference, so switching between the outputs and using only one at a time could decrease electrical interference and improve sound quality.

The fact is that there are relays (the "click" you hear when you switch outputs) which direct the sound to one or the other. Both outputs at the same time is physically/mechanically not an option for this product. The only way to change that is for you to void the warranty and take a soldering iron to your sound card.