Good Evening,
Last week I ordered a quad of Gold Lion Genalax KT88. They came this afternoon. I put them into my Grant Fidelity A-348 and biased them to .48. Within 5 minutes I had one tube get bright red. It was red for about 3 seconds. A small burn mark, the size of a dime resulted. I quickly shut off the unit. I then let it cool for a few minutes. I then turned the bias low and turned the unit back on. I started with .4 and in 20 min increments moved the bias up to .48. It has been on for four hours now and it seems fine. Sounds fine. Nothing lookes burned, cracked or broken inside. I know there is a break-in period. But I mean that channel, the right, does not sound different than the left. Do you think there is any damage to the tube?
I await your reply and thoughts.
REB.