Concur with positive comments above re the KT-150 tube. I just upgraded my ARC Ref 150 amp to SE status. The SE upgrade includes KT-150 tubes. Bottom line: my amp sounds noticeably better.
See the ARC Ref 75 SE and Ref 150 SE threads that are still active for more comments.
See the ARC Ref 75 SE and Ref 150 SE threads that are still active for more comments.