Anyone else find it strange that the “headphone out” jack is S/ PDIF? This would mean that the cable is sending an encoded digital signal that would require decoding by the receiving device!
If the Jack is truly outputting S/PDIF, then it must go into a S/PDIF input on an interface.
If it’s not S/PDIF, then yeah, 3.5mm to correctly wired 1/4" y-cable would be the way to go.
Is there some way in the laptop audio settings to switch the headphone jack from S/PDIF mode to straight stereo audio?