Nice tubes, the falcon logo is irrelavent though.
I've tried over 50+ different 6DJ8/7308/6922 tubes
for both phono and line stage in preamps.
If that's not enough for you then I don't know what else to tell you.
Yes, I do own Telefuken 6DJ8s. If you don't mind microphonic then you can try the Telefunken 6DJ8s. It has nice soft mid range in a preamp, but lack of authority in bass and not enough spark in the high frequencies.
I'm going to try the Siemens 7308 you recommended. Meanwhile I got a hold of the telefunken 6DJ8 2 days ago and while my initial impression was that it was really great, I'm starting to feel that the high frequencies might be rolled-off too much for my taste, as you stated. Good thing I can return them.
Can't complain about the bass though. It has mucho authority without any bloat.
Anyone else have any suggestions?