Presonus 1818vsl and Behringer ultragain ada8200 latency problem

Hello!

I have a little problem, and maybe someone can help…
(and hope this is the right place for a question like this)

I always (for years) used ardour and as audiointerface the presonus audiobox 1818vsl. This works perfectly, just “plug and play”.
Now i want to add 8 more mic preamps with the beringer ada8200 (adat mic preamp).
The two devices are synced through adat (presonus as master, behringer as slave).
I get good audio signals, everything works perfect…
EXEPT: the tracks coming from the behringer have a little more latency, (just like 3ms).

Now i have no clue where the problem is or how to solve this.
Maybe it is in the Presonus, like the adat inputs have a different latency than the mic inputs?
Or i suspect that the AD converters in the behringer add the latency.

So: Maybe there is a way to compensate for that in Ardour. Is it possible to apply a different latency compensation in Ardour just for the tracks connectet to the behringer inputs?
That would be great!!

Maybe someone already knows this and has a solution?

And: I use Linux, and Jack…

Otherwise my quick workaround would be to just move the tracks from the beringer in ardour everytime after recording.

Thank you and al the best
David

EDIT:
Ok… it get’s even more strange…
I did the following experiment:
A square wave from the same source is plugged in one channel of the presonus1818vsl and also in one channel of the behringer ada8200.
I record both channells in ardour. The wave coming from the ada8200 is something like 3ms more late, so out of phase. Now: over time they drift even more apart and very interesting,after every 80 seconds or so, the ada8200 jumps back to being like 3ms late… :thinking:

This sounds like a synchronization problem. You should also hear a click every 80 seconds when sync jumps. I would be more inclined to suspect that some component of the Behringer is bad, given their reputation and my own experiences with their devices. But you should test both devices with a third adat - device to find out the culprit. I would also doublecheck every sync option on both devices.

How are you syncing the two devices to each other? Are you relying on the ADAT cable for that? or using a separate word clock? Using ADAT for sync is known to cause problems. Have you tried using the ada8200 as master and does that make any difference?
Each device has it’s own intrinsic delay for processing. For example, my old delta 66 (ice1712 based) adds 1ms to everything while my ART dual pre is about 0.65 ms. 3 ms seems a bit long for something that has no mixer or effects in line. but there may be delay both at the adat send end and the adat receive end.
In general, even with synced devices, I prefer to keep acoustically locked mics on one interface. So all drums on one interface… any stereo pair on one interface.
It would be possible to add a delay to the faster set of inputs too but getting it so there are no phasing issues may still be difficult and so at least stereo pairs should still be same box.

Thank you guys for your answers!

yea, i should try a better adat device. I also suspect the Behringer to be the problem.

I tried every sync option: Via adat and word clock, and in both cases the Behringer as master and slave. All this makes no difference.

…jes, and keeping acoustically locked instruments on the same device is sure a good practice.

I will do some more research and maybe find a solution…

…so i decided to give up.
maybe one could do something by tweaking the settings on the presonus through its software, but this is not available for linux.

so one can still realigne the tracks after recording or put a artificial latency on the other tracks in ardour. Both is not very elegant.

Conclusion: no recommendation for this Behringer device and i try if i can find a presonus 8 channel adat preamp…

anyway, thanks for your help!
David