The tempo slider stopped working when I turned the sync function off.

To keep the tempo from changing suddenly directly after the sync function is turned off, the unit is designed so that the tempo of audio output does not change when the tempo slider is operated until the tempo at the position of the tempo slider matches the tempo of audio output.

Operate the tempo slider in the direction indicated by the LEDs next to the slider. The tempo slider is enabled when it reaches the position corresponding to the playing speed.