Could you please try to help me solve an amp problem I have with my Clark Beauford 5E3 Deluxe? Whenever I hit a louder note there is an ugly distorted tone - it sounds like the blue Celestion speaker is farting out. I hooked up another well working speaker instead but it did not go away. I changed all tubes with exception of the rectifier tube - nothing changed. Do you have any idea what this could be? When I play very soft, the sound is OK. But whenever I play harder, the amp has this squealing distortion. Thank you very much!!!!