I use a 12" carpenter's "torpedo" level.
Ya gotta level your platter to the best of your ability. When mine was off about 1/3 bubble, I was getting the weirdest phase anomalies and balance problems. On one mono album, the sound seemed to come from from the front window to my left--90 degrees left of the point between the speakers.
Using my trusty Sears Craftsman level to get the bubbles to level longitudinally, laterally, and diagonally fixed all this.
Ya gotta level your platter to the best of your ability. When mine was off about 1/3 bubble, I was getting the weirdest phase anomalies and balance problems. On one mono album, the sound seemed to come from from the front window to my left--90 degrees left of the point between the speakers.
Using my trusty Sears Craftsman level to get the bubbles to level longitudinally, laterally, and diagonally fixed all this.