The motors are often knockoffs and the gears are cheap and mostly plastic which lead to sloppy fit which leads to playing at the wrong speed and variations in s

The motors are often knockoffs and the gears are cheap and mostly plastic which lead to sloppy fit which leads to playing at the wrong speed and variations in speed which They also often are only mono tape heads instead of stereo. Check out techmoan and vwestlife on youtube as they have done better jobs than me of explaining the issues.