My VPI SAMA

orthobiz · « **on:** 27 Jan 2010, 02:48 pm »

I started a new topic as the previous one was looking a bit hijacked...

Wayner, my SAMA when connected doesn't spin at all unless I start it spinning. Once it's spinning it's strong, silent and rock solid speed stable.

Maybe I'll call VPI later to see if this is normal. It's a new unit that I purchased from a dealer.

I have heard of some turntables that need a push to get them rotating, can't remember which ones. When turned on, the motor moves slightly to a position of magnetic stability and quivers a little bit. Once I turn the platter slightly, it kicks right up.

Paul

Wayner · « **Reply #1 on:** 27 Jan 2010, 04:17 pm »

I don't think the motor's behavior is typical. In fact, I'd say there is something wrong with your SAMA motor. I believe VPI uses a Hurst motor, the PA series #3228-004. It's rated for 8.5 oz/in torque and should pull like a bulldog, just like my ARMod.

Here is a link. It's the third one down. It is a 300 RPM 120 volt motor with a .85mfd starting cap. Your pulley should be larger then mine, like an 1.50 inch diameter.

http://www.hurst-motors.com/papbdirectdrive.html

Wayner

orthobiz · « **Reply #2 on:** 27 Jan 2010, 05:46 pm »

Here's the answer. Spoke with Mike at VPI. Apparently the new motors in the SAMA are the same as in the Classic. They have a 0.5 capacitor. To mate with the SDS, it needs a 0.68 capacitor or the SDS doesn't "see" that the SAMA needs more oomph to start the platter spinning (sorry for the poor explanation; I'm not an electrical kinda guy). Once I manually spin the platter, the motor will realize the benefit of the SDS.

Anyway, he's sending me the new capacitor and I'll report back when I get it.

Paul

BobM · « **Reply #3 on:** 27 Jan 2010, 05:50 pm »

I think I saw this mentioned somewhere else. The suggestion was that VPI should send the new cap and notes with every Classic in case someone needs it instead of having to dig for the solution or call VPI. Sorry I didn;t remember until I saw your post.

orthobiz · « **Reply #4 on:** 27 Jan 2010, 06:03 pm »

No problem Bob. I vaguely remember seeing it somewhere else also. Maybe the new SDS runs the new SAMA. But my SDS is from this summer so it's not that old.

If someone else does a SAMA search, hopefully this thread will come up!

Paul

Wayner · « **Reply #5 on:** 27 Jan 2010, 09:19 pm »

So they must have Hurst make a custom motor for them. That is a great answer to the problem, starting cap at wrong value, screwing up the SDS. Glad it's getting solved.

Wayner