ES-8 ADAT Output not working - Strange Sweeping Sound

[Samhostettler]

I'm having a very strange issue with my ES8 over ADAT

My setup:
MacOS 10.14.6
Focusrite Clarett 8pre USB
ES8 connected via ADAT IN + OUT (firmware 1.2.0)

ES8 inputs are fine but outputs are not outputting anything for 10-20 seconds then there's a sweeping tone (very aliased) and after about 10 seconds the output goes fully negative (blue). I've recorded this sound if hearing (or seeing) it would help? (it seems to be negative pulses of different lengths)

What's really strange is that it starts on output 8 then about 10 seconds later I get the same tone on 7, then 6 then 5 then 4 then the ES8 pops and restarts then exactly the same thing happens over and over until I turn it off.

During this, I'm not getting any output from the ES8 at all. I've tried swapping the Optical cables around and I get the ES8 input working both ways round so it's probably not the cables.

I've tried at 44.1khz and 48khz on the Focusrite, using ADAT as the clock source

The ES8 has also previously been working fine over USB but I was hoping to use ADAT to get the latency down and also be able to hotplug.

Any help would be greatly appreciated
Cheers
Sam

[os]

In this setup the Focusrite needs to be using its internal clock.

[Samhostettler]

Thanks for such a quick response!
This stops the sweeping tone, but I still get no sound through the outputs.
Inputs are still working fine.
Cheers

[os]

The outputs still work OK over USB?

Are you sure your ADAT cables are OK, and the Focusrite is configured properly? A test for both would be to plug the ADAT cable from the Focusrite's output to its input, and then loop audio around.

[Samhostettler]

Ah, thanks for your help here! It seems for now like it's actually the ADAT output on my Focusrite that's not outputting somehow.