When VPI manufactures or sources components from their suppliers, they are specd to an acceptable tolerance. Variations in motor, pulley, belt and platter tolerance will result in slight speed variations.
For 2 tables to have the exact same speed without a SDS, both will need to have identical motor rotation, identical pulley diameter, identical belt tolerance with no stretch, and identical platter diameter without any deviations between the 2 samples.
If there is any deviation in tolerances between the 2 tables, they will have different speeds. It is simple physics. The SDS is designed to fine tune a table and to factor out the fact that each table will not have the exact same manufactured tolerances and be feed with a stable 60 Hz power.
If you believe that a lower frequency sounds better, then put on a motor pulley designed for a 11 ½ inch VPI platter and adjust your SDS to the low 50 HZ.
For 2 tables to have the exact same speed without a SDS, both will need to have identical motor rotation, identical pulley diameter, identical belt tolerance with no stretch, and identical platter diameter without any deviations between the 2 samples.
If there is any deviation in tolerances between the 2 tables, they will have different speeds. It is simple physics. The SDS is designed to fine tune a table and to factor out the fact that each table will not have the exact same manufactured tolerances and be feed with a stable 60 Hz power.
If you believe that a lower frequency sounds better, then put on a motor pulley designed for a 11 ½ inch VPI platter and adjust your SDS to the low 50 HZ.