Some questions about production and soundcards

[Machete]

Hello

I have some doubts about sound card like for example if i record my mix in my kontrol s4 and then to do master the mix in ableton can I use my s4 like a soundcard?

I have traktor pro 2 sync with ableton too so maybe in that case i dont need to buy and interface or soundcard I better buy a midi keyboard...right?

[koffa]

I don't quite understand what you want to do, you record your mix "in kontrol s4" how? Through Traktor, right? Internally or externally? If you have ableton just fire it up, set ASIO and the S4 and you should be going in no time? Drag the mp3 (edit: wav, where's my head aaaat...) in, don't warp it and mix to your hearts desire... I guess.

[Machete]

Internally so i dont really need to buy an extra soundcard right?
so if i want to make other productions and dont use the traktor just the interface of the 4 can i do that?