Ground loop related to VPI SDS/motor at 45 rpm?

If you haven't oiled your motor in a while, it might be time. Although I never had a hum or noise through my speakers, when I owed an Aries 3 the motor would hum ar 45rpm audibly when I placed my ears around 12 inches away from the motor. I fixed it by tightening the black plastic pully on the motor with an Allen wrench and oiled the motor with a couple of drops of VPI motor oil.

On the side of the pulley below where the belt attaches, on the side of the shaft you should see two small openings 180 degrees from each other. A small Allen wrench fits into both. Make re they are snug. It's how the plastic pulley is removed from the motor and gets loose over time.

If you have a stand-alone motor the are on the plastic flange that covers the motor's metal axle below the pulley.

Plug your motor into the wall outlet and remove he SDS from the system. If you have a pulley that has two different places to put the belt on (33 and 45). Try them both. If no noise, this probably isolates it to the SDS.

Unplug the SDS. Then plug it back in again and try the motor controlled by the SDS again. See if noise comes back.

If you have tried all these things including proper motor lubrication, then it may be time to call VPI and talk with Mike. If you have to call, make sure you have written a list of everything you have tried so it will help him quickly eliminate etiologies and treatments.

Good luck. It sucks when something goes haywire.

If you have a single size pulley, it's meant to be used with an SDS. If you talk with VPI, let us know what come up with and how it turns out.