Thank you "Listens2Tubes. That (tails out) being the case what was the purpose of "Library Wind/Spooling"?
bob w.
I think there are other threads on here that might have a better explanation, but the purpose of the two is different.
Tails out has to do with print-through on 2 track tapes (or any tape that has tracks recorded in one direction only). It theoretically makes any transfer of audio between layers of tape occur after the main sound as a light post echo rather than a "pre-echo" so it should be masked by the main sound.
The library wind is for getting a smooth, even, tight tape pack to protect the tape mechanically from curling at the edges from uneven winding at fast speeds. It also is for more delicate tape handling without having to go through the whole reel at a normal playback speed. If you wind your tapes tails out and rewind normally to the reel you will be playing from, on a reasonably well adjusted machine, then play at normal speed back onto the storage reel you would not need the library wind slow spooling speed. I guess if you wanted to be extra careful with an old fragile acetate tape you might use the slower spooling to transfer to the reel you are going to play from.
Tails out and getting a tight uniform tape pack go hand in hand as good practice for studio master tapes, so that is where the concepts come from.