I normaly use my line6 Mobile in plugged in to my iPhone then audio out to my iPad and cubasis. Today i tried plugging directly into cubasis and i get noise with or with amp sim. It’s the same noise introduced only after playing for a few seconds. Stop playing, the noise doesn’t appear. The input level is between half and 3/4 of the way up so I know it’s not too hot a signal.
I’ve uploaded a sound sample here.
Is this the noise you are getting?
Edit: after restarting the app and fiddling with the Mobile in adapter, I wasn’t able to repeat the problem so it might be something to do with the mobile in. The noise I’m getting is almost like a frequency cycle. But as I said, it’s not there any more. Perhaps you could upload a sound sample. As I am a user of the mobile in device, I will stay tuned to this thread.
Here’s a second sound recording without any extra noise. Vintage amp sim, gain and treble set at 5.
You might try making sure the Mobile In device is properly seated in the iPad jack and also try both guitar in jack and stereo in jack on the Mobile In deviceto see if it makes a different