VPI 300 RPM vs 600 RPM Better?

The 300rpm motor is quieter.

Try this: take the belt off the motor so that the platter won't move, lower the stylus onto the platter, switch on you amp and turn up the volume. Now switch on the motor and you should hear hum.

The hum will come and go as you switch on and off the motor. The hum isn't electrical, it is from the vibration of the motor transmitted through the table and shooting back up to the platter from the cone feet.

If you try this experiment with both motors, you will find that the hum from the 300rpm is much much lower.

I am getting too much vibration from the 300 RPM motor. I putthe 600 RPM motor back in, vibration gone. IMO, the 600 RPM is quieter.

Vibrations can be remediated in this regard. A moongel or sorbothane type pad can be placed underneath the motor pod - remove the rubber feet.

I believe the 600 rpm motor has twice the torque of the 300 motor. I have no 'vibration' problems. When I brush the record with stylus down on my Scout I notice far less speed recession than anything else I have ever owned, including rim drives, DD's and other belt drives.

@Tzh21y, The 300rpm motor definitely should be a lot quieter. That is the whole point of the upgrade. If it isn't, I think there is something very wrong with the motor you bought. I suggest you contact VPI and see if you can have it exchanged.

I strongly suspect that the amount of motor vibration varies quite a bit based on the position of the magnets in the motor which I understand is not very precise.

Small changes in the phase of the motor drive makes quite a bit of difference in how smoothly the motor runs.

You can probably do this by tweaking the phase shifting cap value but the easiest way for me is to use a computer to generate the drive signal using an inexpensive frequency generating software.