ASIO Positioning Protocol - External Sync Nuendo 13 - Bug?

Nuendo
1

I am using Nuendo 13 with external timecode sync to “ASIO audio device” that is the RME 9652.

When I have the buffer size set to 1024 the transport in Nuendo is stable.

However when I lower the buffer size, there is erratic behavior of the transport. It is glitching back and forth in between 1 second intervals in the timeline.

Is this a Nuendo bug or a hardware issue?

Posted this on RME forum and the reply was

“IMHO the hardware expects a simultaneous ADAT input signal that is synchronous to the Time Code, means has the matching sample rate. Maybe I am wrong but that was the typical use case, and might be even more important with a DAW.”
-Regards
Matthias Carstens
RME

Video screen capture posted on Youtube:

2

What is connected to the ADAT port? A tape recorder?

3

MOTU DTP ADAT sync (out) connected to RME

also interesting to note that if I click on the MMC play button a bunch of times it will eventually start playback and seems stable. But if I stop in the middle of playback the audio is horrendous until I move the cursor out of the way of the audio file

4

Which MMC Play? In Cubase? So you sending Timecode?

BTW, in your Hammerfall settings, the ADAT1 is set to S/PDIF. There is no ADAT time code in S/PDIF.
And sync check says ADAT’s are not synced.

Are you aware that word clock is not time code?
And syncing one means not, the other is synced as well.

5

The ADAT sync cable carries both Word clock and timecode, both of which are being received by the RME.

Note under clock source in the above screenshot word clock is set to ADAT sync.

And below that the RME driver shows time code which indicates that it is in fact receiving timecode.

None of this explains why the buffer setting would have this effect though

6

Also, interesting to note that when I change the display driver the behavior changes.

ie. When using the Microsoft Basic Display driver it wont playback at all (with 32 samples buffer).

However, when using the Intel UHD driver it will playback with no hiccups (with 32 samples buffer)
Until I stop the transport. Then all hell breaks loose

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