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VPI SAMA Flywheel (small)

I have one of the last units from the last run of the HW19-Mk IV with the TNT upgrades (although if memory serves, Mk IV denotes those upgrades).

Anyway, recently the SAMA began to make noise, which was more prevalent with the VPI turntable line conditioner (SDS) in place (the older version, not the latest one). When the PS is taken out of the system, the SAMA makes less noise, but is still audible. 

So I took everything apart. I took off the access panels on the SAMA and pulled the motor out of its housing...looks normal. I did put a very small amount of very light-weight oil on the motor shaft, which probably accomplished nothing. The motor is completely silent out of the TT and on my bench. (Whew!) Mine came with the small "flywheel" that fits over the shaft spindle of the motor. When I reinstalled it on the shaft, the noise returned (at a lower level now that the motor is not connected to the rest of the 'table, but definitely audible).
I've cleaned and slicked the surface of both the spindle and the inside of the flywheel to no avail - the noise is still there, so I assume the noise is the flywheel "chattering" on the spindle.

Any ideas?
I can presumably put everything back together minus the flywheel and, I assume, solve the noise problem. 
What benefit will I lose by doing so? 
Just remove it and call it a day? 

Thanks.
mendps
6 responses Add your response
vpi's avatar
vpi
223 posts
 
Wow, Deja's vu all over again.  I have the same VPI rig as you except I ditched the SDS in favor of a Phoenix Eagle and Roadrunner.   About two years ago my woofers started pumping wildly and I could hear a chugging from my subwoofer.  I panicked and started looking for a new SAMA.  That is, until I chatted with a long time friend and former VPI dealer.  He advised that VPI used that little flywheel for a few years until deciding it did more harm than good and stopped using it.  I ditched the flywheel and everything went back to quiet.  Going on two years now since I removed the flywheel with no problems.

If if you watch the motor running with the flywheel you can actually see it wobbling.  That wobble is being transmitted to your platter through the belt and causing woofer pumping.   Bottom line - ditch the flywheel.   P.S. I think the TNT upgrade to the MK III and MK IV involved a heavier platter than the platter that came with the MK IV.
vpi's avatar
vpi
223 posts
 
P.P.S.  I've noticed no deleterious effect from removing the flywheel.  My speed remains constant to within .002 rpm.  

mendps OP
5 posts
 
Thanks for the quick response. I also wrote to VPI and Michael Fremer. I expect to hear back from the former in a few weeks (they are not the best with communication). Fremer usually responds in a few days, but your answer makes that point moot. So it's off with the cheesy flywheel!

My Mk IV came with the TNT motor (SAMA), platter and bearing. I'll look into the Phoenix Eagle and Roadrunner; I'm on my second SDS and not particularly fond of its performance. 

BTW, I made a 3+" thick, multi-layer shelf (MDF and BVD hard rubber) to place under the VPI. I also turned out a separate plug from the shelf which the motor sits on further isolating the motor from the rest of the TT assembly via the plug and a layer of vibration absorbing material. Apart from the belt, the motor and TT don't meet again until they pass separately through about 90# of combined mass. Cost me $50 to make. 

Thanks again.
vpi's avatar
vpi
223 posts
 
I'd be interested to hear what VPI and Fremer have to say.  My HW-19 started out in life as a MK III.  I then did what the dealer said was a TNT upgrade which consisted of the heavy black platter, new bearing and the SAMA in the round, silver colored casing.  If I remember correctly this was before the MK IV came out and VPI called it a TNT Jr.  They later came out with a different table they called the TNT Jr.   I too have been disappointed with the VPI power supplies.  Unfortunately, Phoenix went out of business about a year ago and they can no longer be found.  Very nice base you made.  I've considered doing the same but with a large butcher block.  I've just never gotten around to it.
Cheers
mendps OP
5 posts
 
I'll let you know if I hear back from them. 

I got the idea for my shelf from the Well Tempered TT plinth; which was constructed with a similar approach. I liked the idea of multiple constrained layers to dissipate vibration.  
barrysandy
192 posts
 
vpi already gave you the answer - ditch the flywheel. It’s noisy! Try it without it and you won't hear anything.
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