Yeah, that's a sign of overheating. Time to replace it. Btw, on the subject of using KT77 on a Mark IV, have you read Rabies's post about it?He too fried one of his KT77s.
http://forum.grailtone.com/viewtopic.php?t=23664&highlight=bias
Not suggesting that KT77 doesn't work, just throwing in ideas. In any case, good luck.
http://forum.grailtone.com/viewtopic.php?t=23664&highlight=bias
Not suggesting that KT77 doesn't work, just throwing in ideas. In any case, good luck.
