Subtle timing issues with the audio should not happen. That is highly unusual. Even more so when you say that VST Instruments don’t display that problem, as they run on the same audio engine as the audio tracks do and thus follow the same timing.
There is is one setting in the Preferences that could be checked by you whether it has an influence on timing:
Maybe you can try to toggle this setting in order to find out if it makes any difference.
Yes, that’s what some people do. I’ve never done that, but there are a lot of resources on the web for that kind of setup
You many know this, but many plugins are Zero latency which could replace your other plugins in your workflow.
To display plugin latency in Cubase, navigate to the MixConsole, enable “Channel Latency” in the setup window layout, and then open the “Channel Latency Overview” to see the latency of individual plugins and their cumulative effect on a track.
One thing is 100% sure, this is not caused by the internal clock of your motu! And using an external clock can and will not improve sound quality, cause for a ADDA locking to an external clock is more delicate then to the internal clock. One can only hope that clocked EXTERNALLY audio quality is equal to internal. RME’s steadyclock FS has achieved this goal as do some of the more expensive Dacs.
But clock jitter does not affect timing at all. It causes some very mild, but unmusical distortion, which unless it is extreme (which never happens on internal clocks) is completely inaudible. If jitter was so bad as you experience, pitch would go up and down massively.
This does not solve your issue, but it does exclude one cause, the sample clock. I would try a test session with reaper and see if that has the same issue. If not it definitely needs investigation by steinberg.
Cheers!
