Equalizer 5-band on veroboard too noisy

[JackSkellington]

Hey guys!
I built this circuit: http://www.sabrotone.com/?p=99 and it works, but I got too hum in my opinion, almost like a high gain pedal. Indeed, I can't use it in the overdrive and high gain channels of my amp.
Here's the schematic and other information: http://www.generalguitargadgets.com/effects-projects/eq/6-band-graphic-eq/
(The layout is not the exact copy of that project).

I'm checking the components again, but that seems ok.
Any suggestion?

Thanks!