MTC is inconsistant with Sonar as slave

[Radovic]

Has anyone experienced an inconsistently with MTC. I am using a MOTU express clock with USB out connected to my DAW and MIDI out to my Panasonic DA7 mixer. The DA7 Midi out is connected to a RME HDSP 96/52 to share MMC with SONAR. The purpose of the MOTU exp is to generate MTC to the DA7 for MAX Automation and to sync SONAR on my DAW. After tracking and during playback I am experiencing an inconsistent timing rate where the audio is being played back slow or at normal speed, then fast; the speed fluctuates and is inconsistent throughout the entire song.

When I use Sonar's internal clock I never experience a problem with recording or playback. However, since SONAR does not generate MTC I no linger can use MAX. I know I could use Sonar's automation but would rather have the control and capabilities that MAX provides.

Does anyone have any viable solutions, suggestions, questions? should I return the MOTU EXP and purchase another type of unit? Wait till Sonar does provide MTC? I'm open to any suggestions.

Thanks in advance,

Radovic

 

[Jim Y]

What have you got Sonars MTC sync working at? "Trigger and Freewheel" or "Full chase Lock"?
The former works better with an external word clock and Sonars sync source being the device recieving the clock (The soundcard icon).
For the Soundcard option to be active for the device recieving the word clock, Audio Options needs the record and playback timing reference to be one of the drivers for that device. Can you obtain a word clock signal from the MOTU and feed it to your RME card?

For example, my Audiophile card can recieve word clock thru it's s/pdif input. To MTC sync to a hardware recorder, I have Sonar on Soundcard timing and an Audiophile driver selected for the playback and recording reference. With the Project option for MTC on trigger and freewheel, Sonar only needs start/stop and song position from the external timing reference coming in the midi port, it doesn't actually need to keep time from the MTC as it is using the same reference word clock. Doing this, the timing in Sonar is flawless. If I had another soundcard as well and had that as the timing reference, I would expect the sync to be all over the place.

If you can't get wordclock from your MTC generator, you will have to use "Full chase Lock". Then, Sonar has to calculate it's audio sync from the midi time code. I found this unreliable and it can take a few runs to sync up.

You should always have Sonars timing running from the Soundcard. Internal uses the pc time clock and best used for Midi only projects.