[ninja636]

A good noise gate might help, but I'm not to familiar with Peavy amps. A good one is the ISP Decimatar pedal(also comes in rack mount). That thing is freakin' awesome. The Boss NS-2 (the one I have) adds a lot of color to your tone. I'd try the tube swap, but not the mod. I'd sell it and take the money and add some to it and get a high gain amp. Unless it holds some sentimental value for you.