Managed to solve the syncing problem. The easiest way is to use DAC in direct sound mode.
For an example,
1)Mytek audio device was set to Stereo 192-dsd DAC Out1 L/R (Mytek USB DAC WDM Audio) [Direct Sound].
2) USB Audio DAC (N) [Direct Sound]
And I did the same for the other 8 DACs. JRiver syncs within 10 to 15 seconds and remained in sync through out the listening session.
Occasionally, after a long interval or other intervention it can go out of sync and you need to restart JRiver. Stop and Play would not get the sync to work.
