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VPI SDS speed question

I have a VPI TNT mk.III set-up w/ flywheel. I am using 2 belts, bypassing the hubs as suggested by others. Regardless of how far away I place the flywheel from the motor, I need to reduce the voltage on the SDS to about 55.7 hz. Should I be concerned that the motor is way off? I assume the motor should run pretty close to the 60hz when aligned via strobe disc. Anyone else had this experience?

Thanks,

Jeff
jmslaw
4 responses Add your response
franks
151 posts
 
This is perfectly fine. I noticed the same thing when I changed to the mk5 bearing and platter and stopped using the tripod system/pully. Definatly set the SDS voltage via the strobe disk and enjoy.
yagbol2
66 posts
 
The reading on the SDS should be in the 60hz vicinity. Make sure you remove the tri-pulley so the big belt must go directly to the flywheel. If you don't take the tri-pulley out you will overstretch and strain the belt and your reading will be in the 55hz area.
jmslaw OP
95 posts
 
Thanks for your responses. I did configure the 2 belts correctly, and I still can't get above 55.85 hz. With the tri-pulley arrangement, my SDS was set about 58.7 or so.
yagbol2
66 posts
 
By the way, put the strobe disk on platter using a strong FLOURESCENT lamp. It is imperative that flourescent not bulb or those new energy savers. Better if you have a K.A.B. with a dedicated light source or Clearaudio makes one, too.
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