I just recently bought a Behringer UMC1820 which is otherwise performing perfectly and seems to match all my requirements. However, I noticed that if I re-use my previous sample setting for input/output delay Ardour’s track recording is still slightly “off” the beat (I tested by recording the metronome from ardour and routing that straight from output -> input). If I re-do the delay test in Ardour then I get a slightly different delay amount (usually within ~10 sample rate difference, but at least one point it was 20 samples faster than usual), and then I re-record and the recorded click lines up again.
Is there something wrong with my audio interface? Or is it to be expected that I have to re-run the audio config wizard each time I record to get the recording perfectly in-sync?
Also, I’m a little concerned since most of my recording done is via SPDIF which I’m not using for the delay test. Wouldn’t SPDIF have a different latency since there is no A/D conversion?
I also tried starting/stopping different programs and it seemed to have little to no effect on latency.