well- the JAN 6L6wgb were disappointing. kind of dull and lifeless even after rebias. then when removing them the center plug with the notch on it snapped off of one. Fortunately it did not get stuck in the socket. So, I put in some telefunken 6L6gcs. really good. very hi-def. TAD6L6WGC-STRs also very very good. I'll leave the TADs in for a while. They came as a matched pair but are a good 5 mv apart. Sounding good so far. I might go back to the JJs. They sounded great, so if its not broke, don't fix it.