Focusrite Saffire Pro40 as standalone with Clarett 8Pre USB Nuendo 10.3

I recently purchased a Focusrite Clarett 8pre USB interface and thought I would use my Saffire Pro40 (Firewire) to increase my inputs. After configuring the Saffire as a “standalone” interface according to Focusrite’s instructions (at least I think I did) and connecting the optical cable, I can’t get a signal into Nuendo. I added the inputs from the Saffire in the audio connections as ADATs 1-8.

Can anyone give some advise as to what I’m doing wrong?

That should work fine …but regarding the ‘silence’ - it’s a bit of a long shot - but assuming you have configured everything properly - you are going to need to think about digital ‘clocking’.

Looking at pictures of the Pro40 it doesn’t look like it has ‘wordclock’ so you are probably going to need to make that the ‘master’ and set the clocking of the 8pre to ‘spdif’

does that make sense ?

and I’m guessing you followed this ?

yes i did thank you

The Pro40 hardware says that it’s locked and the clarett control says that it’s synced

the Pro40 says it’s synced because it is the master - and clarett control is synced to what ?

I’m not sure that the digital clocking is the issue here - although it definitely needs ‘fixing’ - free running clocks normally manifest themselves as periodic glitches and clicks - not total silence - unless one is 44.1khz and the other 48khz ?

do the meters (?) on the pro40 show signal ?
do you have anything else you can use to feed ADAT to the clarett ?
the TOSlink connector can be configured as spdif and ADAT - is it definitely ADAT ?