Hi Dai.

Select the Tyros as the MIDI output driver, but don't check the box to re-route MIDI output to the dafault synth. This should send all the MIDI data to the Tyros.

It should still allow playback of any VSTi instruments as long as they are loaded into an individual track and assigned a MIDI channel and port.

You will probably need to turn off any MIDI channel on the Tyros which is also being used for a VSTi, or both will play.

Hope this helps.

ROG.