[Mr. David Severson]

Hum can be introduced from many sources. Have you tried recording with your monitor off. Is your guitar cable pooched? is your amp near any other sources of electrical output? Is the cable from your G-Dec ok aswell? Make sure all connections are firm and in place you may also be experienceing partial connections which also cause hum.

I live near some radio towers and on some days the interfearence is so bad I can't record. I usually have to find the "magical sweet spot" with my guitar cable by moving around the room until the interfearance is reduced.