so far it’s been 2+months with the Linlai 845 tubes. I have jbl Everest dd-67000 speakers, driving my speakers with Komuro SET amps, pushing at 25watts output. So far the Linlai can bias really high without any problem, once in a while my filament fuse on the amp would trip, even when i swap tube from one side to another the same output tube would break the fuse. I am pretty sure it has to do with biasing the tube too high, which i plan to lower the bias point. Linlai 845 has good output rating, never would run out of gas, my only complaint would be the bass on the Linlai sounds stiff ( bass doesn’t blossom ) could be that the bias point is set above it limits. Overall it’s an ok tube nothing too excited about it. If i don’t need the wattage, i strongly recommend the Shuguang 845 type C metal plate, to my ear it sounds even, has a nicer tone and overall a better sounding tube then the Linlai 845. Again, only if you don’t need the wattage and your speakers are efficient enough. I still like the United 845 better than the Linlai, Shuguang and RCA.