Recording vocals with garage band and tascam US-122L

I am trying record some vocals onto garageband and the interface I have been using is a tascam US-122L. The problem I am having is that it clips all the time, no matter how quietly I have all the settings - even if I can barely hear myself it clips. Is there a setting in garageband that I can adjust - apart from the obvious volume controls when you are recording - or is there a different/better interface that would stop this happening? Any advice would be very much appreciated.