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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
mijostyn's avatar
mijostyn
8,570 posts
 
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.
mcwatson OP
7 posts
 
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
yogiboy's avatar
yogiboy
5,662 posts
 
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...

mcwatson OP
7 posts
 
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.
yogiboy's avatar
yogiboy
5,662 posts
 
The 3 prong outlet is grounded. The 2 prong outlet is not grounded.
Use the 3 prong outlet!
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