"What's Audiojingle? It suddenly appeared on my MacBook Pro's volume output control. Can I delete it?"
No. You should not delete the Audiojingle device from your Mac. Actually, the Audiojingle is a virtual audio device that helps TuneFab software record music playing in the background. If you delete this device, the function of TuneFab Apple Music Converter or Spotify Music Converter will be seriously affected.
However, if you are stuck with Audiojingle being the default input and output sound device on your Mac, please contact us for further assistance by submitting a request here.