Disclaimer: This is most probably not an Ardour issue but Jack/Linux/Focusrite!
I have a Focusrite Scarlett 18i20 3gen that is hooked up to a Ferrofish A16 via ADAT. Got the Geoffrey Bennett alsa-scarlett-gui working. If i stay ITB and just playback the Master out everything works fine.
Ardour also recognizes the I/Os from the 18i20.
BUT …
if i add hardware inserts to access my outboard gear i come to a point where i get massive audio drop-outs. The CPU is at 10% still so it’s not a performance issue. I tried with ALSA as well as JACK (i’m not the expert in the JACK settings by all means so user error is very possible).
I had similar issues on windows which got solved by changing the ADAT preferences in the Focusrite Control software. But i don’t see this feature in the alsa-scarlett-gui.
System:
UbuntuStudio 24.04
Ardour 8.12
AMD Ryzen 9 3950X
32 GB Ram
Focusrite Scarlett 18i20 3gen
Ferrofish A16
Update: Posted the issue on Mastodon to get input outside of this forum as well. Got a response from @x42 for possible clock issue. Thanks Robin, will check that!
Are you having actual xruns (as in counted in the ardour’s upper right corner) ? If not (and if the hardware clocks are properly configured) , double check your adat connections or change the cables, a tiny crack or misplacement can cause this exact issue.
No xruns, just audio getting silent for tiny bits of time.
I also suspect the clock / ADAT connection. cable should not be the problem because same setups runs fine in windows. So “just” clock configuration under Linux i suppose (which i have no clue about atm). Robin gave me a hint as said in the update. But if that solves the issue i have to test.
For years, I have found ADAT clock sync via the ADAT cable to be unreliable on a variety of different hardware. That was repeated a year ago when I switched to a Focusrite Scarlett 18i20. With my Yamaha console as the master, significant number of clicks when synced via ADAT. I bought a long enough BNC cable to do word clock sync, and it fixed the problem. Then I accidentally found that setting the 18i20 to be master and using the ADAT cable worked too!
Thx for all the hints and for the double effort replying on my Mastodon post AND here as well!
Yes, clocking is a nightmare and i don’t even like my kind of working setup in windows. Good to hear that Linux at least has clock source management. Will test your hints and report back.
