The ADI-2 Pro is still connected to the UFX+ via ADAT cable.
Clock Source is set to AUTO.
The State Overview shows Clock Source: SPDIF.
If SPDIF also covers ADAT then I would say its synched by the UFX+ via ADAT.

Funny is that I could reproduce it also a 2nd time after a reboot of the PC.
In both cases (before and after reboot) the 2 Octamic XTC, connected to the UFX+ via MADI, were powered off.

Now I powered on the 2 XTC to record the distortion (as the mics are curr. connected to XTCs) and repeated the test.
But now all runs stable since much longer time (~30 min).

TBH .. I do not know at the moment
- whether the issue is always reproduceable, as I just discovered it or
- whether there is a relationship to the 2 XTCs connected via MADI, whether its power status (on or off)
  could also impact synchronization.

EDIT: if I configure clock to be internal on ADI-2 Pro, then distortion happens slowly again.
Then I changed back to Auto. At the moment dropouts still occurr, waiting now whether it comes to distortion again.

Thanks Matthias for your suggestions, I tried all but it doesn't change the situation.

I ensured that the ASIO Buffersize of UFX+ and ADI-2 Pro are set to the same value, currently 128

The ADI-2 Pro is in USB Multichannel Mode and connected
- to the UFX+ via ADAT IN (and now also OUT) and gets for the input "SP op" a lock @ "44.1" state "adat" Bit "16"
- to the PC via USB, I tried both USB3 and USB2

The SP sign in the status bar is always white, never Red.
The ADI-2 Pro alone has no issues. Only if the 2 devices are operated together !!!

In regards to the USB connection .. My Supermicro X10-SRi-F mainboards chipset (Intel C612) offers:
- 4 x USB3, only the 2 on the back being in use for UFX+ and ADI-2 Pro and
- 8 x USB3, only 4 in use, 2 on the back for mouse and keyboard and 2 for eLicenser/iLok2 (via "Slotblech")

UFX+ and ADI-2 Pro are connected directly to the USB2/3 ports on the mainboard/PC, there is no hub in between.

Here a list of USB ports on mainboard and my assignment:
I only use
- 2 of the 4 USB3 ports
- 4 of the 8 USB2 ports

Hi Matthias, thanks for the hint

Maybe this came from using an USB3 extension wire for the ADI-2 Pro.
Now my setup should be "clean" with straight through quality USB3 / USB2 cables.

But I am gettings still issues, no matter whether I connect the ADI-2 Pro to USB3 or an USB2 port (2a, 2b below):

1. Quality USB3 cable, 3m, from UFX+ to USB3 Port
2a) Quality USB2 cable, 3m, from ADI-2 Pro to USB3 Port (the USB3 port besides the UFX+ on the back of the mainboard)
2b) Quality USB2 cable, 3m, from ADI-2 Pro to USB2 Port

This time I kept the driver settings window open and can confirm, that it has nothing todo with transport errors.

Here an example recording with Mic at the Phones, but sadly I dont get it at the point where its completely messy.
It starts with knacker very early, needs then around a minute to produce eventually a loud hissing spike like nearly at the end of this recording. But over time it then exponentially gets worse, then comes back to knackers and so this seem to repeat.

https://dl.dropboxusercontent.com/u/961 … rungen.mp3