i had this unit on a second hand car i bought, as the online manuals are in Portuguese and spanish had to fiddle a lot to adjust the controls to adjust bass treble balance press on SEL once or twice or thrice as the case may be then rotate volume control for adjustment to adjust clock, turn off demo and host of other features press SEL and hold for a few seconds, press channel up/down buttons to scroll through the features and use the volume control to change (time ect)