Thanks for the answer and offer chinook9; pm sent.
I figured that tubes would probably need a signal to burn in effectively. I don't like to leave my electronics on while I'm gone and because my headphone rig is by my bed, 24 hour/day burn-in doesn't work out. Maybe the pink noise generator wont bother me at night. Might even help me to fall asleep!
The Rft 12AU7 still isn't here but the TJ Fullmusic 12AU7 has about 35 hours of music burn-in. I'll wait for the RFT to arrive to do a serious comparison but I do have to say that so far I've learned something very important. Tubes need more that 5 hours to burn in! Kind of a duh moment. I know the importance of burning in headphones (AKG K702's!), speakers, interconnects, DAC's, etc. so it should have been obvious. Guess there was a little bit of fear of burning out a tube prematurely by leaving it run for days.
If I hadn't been swapping back and forth between the new TJ and the Tungsol 12AX7 cryo'ed gold pin (many hundreds of hours on it), I might have chalked the improvements in the TJ up more to my imagination or 'ear-burn-in'. By swapping back and forth and comparing the two as the TJ increased in hours, it was obvious that the TJ was improving quite a bit for the first 20+ hours. New out of the box and with less than a minute on the TJ it lacked soundstage depth, the treble seemed glassy and too forward and bass wasn't as tight and it was fatiguing to listen. To my ears, if the Tungsol = 100, the TJ = 70. After about 25 hours the TJ = 95. It's so close now that I don't know if I could tell the difference in a blind test but I'm still getting the feeling that I like the Tungsol a little more. It seems slightly more extended in the highs and sounds punchier in the bass region. Hard to say when swapping out tubes, adjusting the bias and then accounting for one tube being colder (temperature) than the other takes long enough that the audio memory has faded some.
I hate to say it but I don't think I gave other tubes enough of a chance to burn in. I think the $40 NOS tube I bought about a year ago (came in an RCA box) probably got less than 5 hours of use before I decided it sounded too veiled. The 6N23P that came with the Project Horizon may not have gotten much more than an hour. Maybe I should try putting some more time on the 6N23P and see what happens.