Dude, you've posted this twice. All you need to do is "bump" the old thread (by posting in it again), and it's back to the top of the list.
The basic solution for hiss is a noise gate (or noise suppressor). However... you said the SansAmp BDDI stopped the hiss. That's not something the BDDI is exactly known for... so I want to ask a few questions about the hiss.
First of all, is it actually HISS, or BUZZ? They're two different problems with two very different solutions.
If the noise stops when you touch your strings or the bridge of your Schecter, then it's buzz. A noise gate will NOT solve that problem.
If it's a continuous hiss, and NOT a buzz, then touching the strings or bridge won't do anything. A noise gate can help, but it only fights noise in between notes.
Also... how are you setting the EQ on your basses? On your amp? What effects are you using (name specific pedals)?
Help us by giving us a better idea of what's going on. Boosting treble, for example, will boost hiss.
