Latest Realtek HD Audio Driver Version

pietcorus2 said:

" Is there a SPDIF connector "............dont know , how can I found out ??
Only connected with two coloroud input-plugs on the backend of PC.

Should be mentioned in the MB manual, normally 2 or 3 pins connector for digital sound transfer to an external DAC (Digital to Analog Converter. That way you are not dependent on CODEC chip on MB.

pietcorus2 said:

Did some study in my ASUS Z97-K manual ; internal connectors ; 1x S/PDIF outheader

Do you mean this connector , and am I connected to it ??

That's the one but if you don't have external DAC you are not connected to it.

pietcorus2 said:

" external DAC "................??
sorry , I still have a lot to learn ....!

DAC = Digital to Analog Converter. gets digital signal from PC or other device and converts to Analog signal for speaker(s), Some have amplifier and some don't. Could be by wire S/PDIF or optical cable. There are some using USB and do same thing. Advantage could be, no interference with longer cables, on some much better sound with appropriately good speaker system, better adjustments and effects etc.

pietcorus2 said:

OK, but do I use this , at the moment ( ??) , only 2 Bose external speakers on two plugs in the PC , nothing else !

No, you are not using it. You are using analog speakers with amplifier(s). With en external DAC, you would plug them in it.

pietcorus2 said:

I see, so this external DAC is a hardware tool , you use for headphone or speakerset...............?

Exactly
[GUIDE] DACs and Amps : headphones
Best DACs of 2018 | The Master Switch
The best DACs | PC Gamer
etc. etc.