How hot are your bass pickups, and what is the treble setting of the bass?
In general, more treble opens you up to more hiss, most especially when you are dealing with a pedal that has gain. The Character knob is all about rolling off and rolling on highs, so anything past noon is going to be very trebly. The Bite switch itself is a boost to the highs/treble to make your sound have edge in a band mix. Doing both at the same time is a ton of treble boost, so you will naturally get a bit of hiss from the hotness of the signal in those frequencies. If your bass is active and/or if you have your treble knob rolled up, it's only going to exacerbate the issue.
Originally Posted by Jazz Ad
There are three main bass tones : boom boom, cling cling and grrr grrrr.