I just built my own guitar and a really cool trick i've come across that works is...
Aluminum duct foil.
Coat your pickup cavities with it, the tone/volume pot cavity as well. The thing should glow silver It made my amp quiet. If this works for you, you could probably turn the threshhold on your ns2 lower and get some of your frequency back.
One thing you need to do though if you do this is ground your shit. I took some pickup wire and tore off the plastic on the tips of the wire and used a screw to hold it down onto the aluminum then soldered the other end of the wire to the tremolo plate in the back. (use an ohm meter to measure resistance and see if you have a continuous circuit on every piece of foil.)
If your amp only has a 2 prong power cable, try getting one with a ground on it also, try using different outlets etc.
If you're looking for an actual pedal, i've heard great things about the rocktron hush.
Finding what is causing hum in the first place is a pain in the ass.