what are you tryin to do with it?? do you know how to use a limiter?? i have also just bought one, n it works perfect as a very transparant limiter.
i like the enhancer around 9 o clock for a tiny bit extra bite, any further and yeah you get hiss, but unless you have got a high treble amp (your a bassist, why would you) theres practically no hiss at lower settings.
if you have played around with the knobs and have no effect, then theres something up with it. the enhancer is pretty extreme at max settings, not in a good way either, but used sparingly its great. i use the limiter to tame the volume boost i get from runnin a fuzz into my filter, works great.