Sota Comet Grounding question


Hi,

I recently picked up a Sota Comet with a Jelco JA 250st tonearm for cheap because the arm needed rewiring. It was my first time rewiring, I used cardas wire and tags, and attached a ground wire inside the arm tube as well as one attached to the arm base. All the wiring connects to a terminal in the chassis, where the rca cables are soldered. The two ground wires connect to the grounding cable which runs to the lug on my preamp.

The question I have is regarding the ground lug that is at the bottom of the chassis. It looks to me like this lug connects to the motor. Where do I connect a ground wire from this to? I am getting an awful lot of static whenever I touch the platter which can be heard through the speakers, and occasionally when I touch the tonearm. There is no hum and everything sounds fine when a record is playing, but as far as I can tell the chassis is not grounded to anything which I’m hoping once this is done could solve the static issue. I tried running a ground wire from this chassis lug to the same lug on the preamp that the tonearm is grounded to which did not resolve the problem. 

Can anyone help me resolves this. I don’t get static from my Thorens or Rega tables, so I hope this is specific to the Sota turntable and can be easily fixed.


mcwatson
MC, the motor and chassis should be connected to house ground. If there is not one already you might try connecting a wire to the main bearing then to the motor then to house ground. If this does not work call SOTA. They are usually very helpful. 
Thanks, I contacted Sota and they said the chassis ground should be connected to the preamp. I still get a lot of static this way. The bearing well is some sort of Teflon or plastic so I can’t add a wire to that. I may revisit my tonearm wiring just to be sure I didn’t miss anything there and then try a humidifier or something like that.
I agree i had a SOTA Cosmos it it made a big popping sound grounding the motor fixed the problem.
Hi ebm,
Out of curiosity did you ground the motor to a preamp or amp or directly to a house ground? Connecting to my preamp isn’t working but maybe I need to make sure all the grounding posts in my system are more secure. I don’t know how to ground directly to an outlet. Thanks!
My SOTA cosmos has never had any issues.
mc, if it is static electricity on the record try one of these.  https://www.sleevecityusa.com/Antistatic-Record-Cleaning-Arm-p/tac-01.htm
The bristles are conductive carbon fiber and the arm is connected to ground so it shorts the record out while it is playing and sweeps any incidental dust out of the way. The static is being created by the stylus rubbing the groove. Unfortunately for us vinyl is at the very bottom of the triboelectric series. It loves to hold on to stray electrons. 
When you set up the sweep arm you want to adjust the weight so it just barely touches the record. The sliding weight gets knocked out of adjustment easily so I slide it all the way to the front and crazy glue it in place. Then I adjust the tracking force with the threaded counter weight at the back. I put some thread locker on it so that it holds it's adjustment.
I have been using a conductive sweep arm for decades and never have any problem with static. I would never live without one.
Thanks I’ll give that arm a shot. I do feel that because my Rega and thorens tables play without any static issues there could still be a grounding issue with the Sota. Maybe I didn’t ground the arm and chassis correctly so I’m gonna re-visit that wiring. The jelco arm has two ground wires so maybe something is off there
If you want to ground directly to an outlet you will wrap a wire around the screw that holds the outlet cover to the outlet. That should be a good ground source. It looks like this!

https://www.zoro.com/hubbell-wiring-device-kellems-duplex-wall-plate-1-gang-silver-ss8/i/G3440123/?m...

Great, thanks for that! I’ll give this a shot before I mess around with tonearm wires. Just curious if it make a difference if the wall outlet accepts two prongs versus three of I go this route? I have two different outlets near my rack and have both options.

sorry everyone for all the questions. Up til now I’ve just had to plug everything in and not think about all this.
The 3 prong outlet is grounded. The 2 prong outlet is not grounded.
Use the 3 prong outlet!
Wow, almost all my outlets are two prong in my old NYC apartment. Guess I should contact the landlord about that. I’ve had to use a power strip for the amp and preamp because I only have the one three prong outlet near my audio rack
And thank you for all the useful tips!

I doubt that the 3 prong outlet is grounded. Over the years it was most likely replaced and someone used a 3 prong outlet ( with no ground ). You should have it checked out . An inexpensive voltage tester like this will verify if that outlet is grounded!
https://www.homedepot.com/p/Power-Gear-90-300-Volt-Circuit-Tester-52060/203744891?mtc=Shopping%7CG%7...