Audio records with noise

For some time I use my soundcard ‘Octa-capture’.
I use channel 1/2 for the Tyros3
I use channel 3/4 for the Korg Kronos
Output 1/2

Without the computer there is some noise, but it is negligible.
By starting my computer the noise is still acceptable, but …
after starting Cubase the noise increases a lot!
The noise is changing constantly, in particular by moving the mouse, opening a menu, click on buttons.

Is it caused by a computercomponent?
It is also audible in my records … I hope you have a suggestion what could cause this.
Thanks for your help!

If you are hearing noises related to your computer input, it’s usually caused by a grounding issue somewhere.
Make sure your computer and audio interface are properly grounded. To test, try running your soundcard off another power socket in the house (use an extension lead to get it to your pc :wink:), see if that makes a difference.

I had the problem with the first Tyros years ago. In my case it was the USB connection between the tyros and the computer. After changing that to standard midi cables the noise was gone. MIDI uses optocouplers to prevent ground loops, and USB doesn’t.
Worth a try if everything else fails.