Another tube question


A tube in my Line Magnetic 216 won’t bias.  I’m assuming it’s dead.  Still glows. Amp sounds horrible.Its a KT 88. Have done an Amazon search.  Any suggestions on brands I should replace with?  Upgrade suggestions?
udog
JJ makes a blue glass KT88 which is quite nice.
Gold Lion. Takes a few hours for them to settle in but worth the wait once installed. 
Until the prices come back down, for my beloved GE 6550As(imagine that): I'll probably stay with the Gold Lion KT88 repops.