Finally, finally sorted out the No audio in headphones/desktop problems that has plagued me on one laptop for the past few days. However it involved a complete reinstalment of OBS, including allowing it to remove all scenes and settings before it worked. BE WARNED ABOUT THIS BUG. Something had taken over the output settings for OBS alone (all other Apps were working fine), diverting the audio to who knows where. I've now got to go through all the settings to try and ensure they are suitable for streaming again. Not best pleased.