Music starts early

Sorry to disagree but LP groove echo, not tape print-through, gets my vote as the most commonly perceived occurence by the home listener. Like many, for years I thought groove echo was a playback induced event. It's not. Groove echo is an artifact created in the LP cutting and plating process, independent of the master tape. See Bob Ludwig's explanation:

http://members.tripod.com/~Vinylville/groove-echo.html

Certainly tape print through pre-echo exists and causes problems, but I doubt it's the one that we're most accustomed to hearing.

I'm completely in agreement with Rockvirgo on this. Here are my reasons. It is standard, no mandatory practice in the recording industry to store tapes tails out and yet all vinyl recordings show this effect to some degree or another. The degree to which it is audibly apparent is proportional to the degree that the cutting is modulated. The end of the argument is this: I have many recordings on vinyl that were tracked and mastered digitally and never "saw" an analog tape. This is conclusive evidence that LP groove echo is at work. Plus the music is heard exactly one revolution of the LP before the main music kicks in, and there is no way that one revolution of a tape reel corresponds exactly to one revolution of LP every time.

And Lugnut, you are incorrect in the assumption that the music would be reversed. After all the LP, and hence the modulated adjacent revolution is still rotating in the same direction.

It would also be one channel "only" if your argument held up. Every track has a blank lead in groove. The left channel would be picking up right channel only information and nothing from the blank lead in. So, again, if your argument held up the right channel information would be a weak signal in the left channel speaker with nothing in the other channel. Sorry, I can't buy into anything other than tape bleed through as so thoroughly explained by Scouser.

Lugnut, the echo isn't coming from the stylus improperly picking up the adjacent groove, the stylus is tracking the info that the lacquering and metal mastering process created and left behind. As you note the entire groove echoes the one next to it. The of necessity soft nature of the lacquer encourages this. Like a sound echo you make with your voice this one is made by the cutting head deforming its surrounding environment, however slightly. The blank lead in grooves are especially affected because they have no signal cut into them to override the echo. As noted in the Ludwig article, the longer the lacquer sits before making the metal master the more the echo cures into the adjacent grooves.