Just because the tube fits the socket, doesn't mean the amp runs the tube.
Bias is set on the amp. Changing tubes doesn't change the bias. 50 to 90 is nothing in terms of harm, certainly nothing to cause such a show as this.
Clearly you have other problems. The lack of relevant details and providing irrelevant info being a bit of a clue as to the biggest one.
Bias is set on the amp. Changing tubes doesn't change the bias. 50 to 90 is nothing in terms of harm, certainly nothing to cause such a show as this.
Clearly you have other problems. The lack of relevant details and providing irrelevant info being a bit of a clue as to the biggest one.