Strange noise trough all channels?

[Fr3d]

Hi,

I bought an Motu Ultralite Hybrid MK3 from Ebay.
I installed the latest audio driver on my OSX 10.10.

The Motu is connected via Firewire and two other USB powered controllers where connected, I was DJing with Traktor for about 30 or 40 min. and suddenly a noise appears after a couple seconds it was gone.

I figured out, when I start Itunes this sound appears:
https://youtu.be/P-SjbMAUnaE

But I dont know why?

I reinstalled the driver, made an Firmware update and right now its working again but I dont know for how long, does anybody knows, where that sound comes from?

Thanks