Howdy. I got an SVT-HD. It is giving me problems. It was fine at last practice (march 28th), Today I turnbed on the amp and heard what sounds like a distorted sinewave. When I play through it, it sounds like there is a very heavy chorus. The real tone of the bass is buried behind the nosie and mud. I checked all my cables, all my switches to make sure it wasnt a cable or Impedance issue. We then tried plugging the amp in to guitar cab with the same impedance and the noise still came through. We then tried plugging a guitar into the amp, same noise. We tried plugging it into another outlet. Same noise. We took it apart and checked all the tubes. They all glow orange and look normal, pre-amp tubes included. I tried changing all preamp tubes. But the noise comes on when I bring it out of standby. Anyone handy with troubleshooting? Hopefully its not a transformer issue. Maybe a bad capacitor? Anyone?