So where you create a song in uTool, you have an option to set up mixer levels for the song. If you export that song to USB drive then play back on the uTrack the uTrack will load the mixer parameters from the song. So you don’t need to have a uTool connected.
If you want to change the levels during the playback you can do that as well.
You can change the levels on the fly from:
-Front panel of uTrack –> then you can save the new levels into the song
-uRemote mixer functionality –> you can save the new levels into the song.