[BScout]

Sync IO won't work with any modern Pro Tools version. That is why. Only the Sync HD and the new Sync X are supported on Pro Tools versions 11 or later.

Loop sync only is useful if you have more than one interface. You appear not to. In addition, on the MTRX, it runs on its own internal clock but references the external clock fed to it to find out what clock it should be. There is no point in anything being a "master clock" for the MTRX. It has its own internal clock all the time. DADman just lets you set what it references. DADman is the control software for the MTRX (it isn't a "when using" situation.) Whether you have DADman open or closed, the settings that DADman gave the MTRX are what is happening.

If you have an HD Native card or HD Native Thunderbolt box or HDX card, you can use a SyncHD or SyncX box. If you do not have one of those three things, then you can't hook up the SyncHD/SyncX box in any useful way.

On top of that, unless you work to picture/video, there is no point. The MTRX clock is better in the first place. What is your point in using a Sync box?

(And once again, the "Sync IO" box version will not work -- Pro Tools no longer supports it. So if you bought one for cheap, it's already trash)