Topic: New qestions @Babyface (Preamp, external HD issue?)

Hello RME, new to Babyface. Two questions:

1) is possible to switch off the AudioIn preamp, since I am working with a tube channel strip?
No criticism @RME quality of the preamp, but simply my way to audio

2) observed a test tone like sound (above 12k I assume) generated by Babyface when an external HD with is connected via the Express Card slot.
Tried to connect Babyface directly to the Notebook, without hub, with hub, etc. always the same observation. Seems there is a bus conflict..
Any idea?
This sound mentioned is not generated, when RME FF is connected.

Greetings

White L.