Well, I've got a bit of a situation on my hands. First topic... I've got an Ampeg SVT-4 Pro that I've had for maybe...a year? Well, as of today, it all the sudden in the middle of playing began to just feed back VERY loudly. I've tried replacing all the cords, and no matter, all it emits if this very loud buzzing sound. My only guess is that it's the pre-amp tubes that were shot...fairly surprising, as they should last FAR longer than a year! Anyone have any idea what it would be? Also, any ideas of the cost? Second... Upon removing a rack drawer from my rack to put in something else, I noticed that two of the screws are stripped at the screwdriver insert...pretty much completely. The unit in there can't be removed as far as I've because of it. Anyone have any ideas about how to get it out? It's a two space unit, and (of course), the screws are kitty corner to each other. The lower one MIGHT be accessible from behind, but the upper definitely isn't. Any help would be greatly appreciated! Thanks!!!