If it's not fixable, then why break it? That's what I always say. On the other hand, if it's breakable and the parts are available, then it's fixable. If your speakers honk then stick with tubes. If they don't then you have a choice, but don't let Murphy's Law rule your decision either way. "I didn't get where I am today by letting Murphy's Law run my life" (from my favorite BBC series - kind of).