Today, while I was practicing, I noticed a sound coming from my amp, very hard to descrive. I put my ear to the tweeter and it's definitely coming from the tweeter or the tweeter is amplifying whatever is wrong. When anything gets close to the pickups on my bass, the noise intensifies. Also, the noise comes and goes in volume swells. It's not the cables - I just got a brand new bayou cable today and there is still the same noise as with my monster. Anyone know what this is or how to fix it?