-How did you set the gains when you tuned the amp? If this isnt done right, you could possibly have the gain or input sensitivity too high. You could be picking up more noise than it needs to. Try lowering it. Kinda a cheating way to do it...but :uhhok:

-Try moving the ground on the amp? Pick another location and see if that makes a difference.

-Hate to say it, but it can also be your Pyramid amp. They arent known for making the best amps :uhhok: