Hello there, I was just wondering if any of you could give me some advice as to what might be going on with my recently obtained 300T. Initially I had a fuse blow, and after replacing it everything was normal. Then, at a gig, 2 more fuses bite the dust. I was worried, but needed to make it through the gig, so I put in 2 replacements and finished the set. I'm now worried this may have been quite the mistake. The next time I tried to use the amp, if I turned the volume up beyond 3 or so instead of reproducing the note I would get shrill feedback that only goes away when I turn down the volume. Also, if I leave the volume down the notes ring but have distortion. I've tried isolating the various power tube pairs as well as trading out the preamp tubes. Any idea as to what else I should be looking at? I love this thing when it is working, but now I'm completely rigless.