Rega RP1 Noise

[Karl5150]

 With digital sources both the Stereomour II and Crack are virtually silent. (The Reduction adds a little non-volume dependent noise) 
With the Rega plugged in to the mains I get a substantial amount of volume dependent noise that actually diminishes when the the TT is switched on and running. Unplugging the RCAs makes no difference, only unplugging it from the wall gets rid of it. (There are no other outlets close by that are not on the same circuit.)
This is a fairly new development after 4+ years of moderate use. It uses a 2 prong plug and there is no ground wire on the RCAs or ground post on the motor housing or plinth.
I am hoping someone has insight into whether the 24V motor upgrade is a cure.
TIA,
Karl   

[Paul Birkeland]

See if touching a bare wire to the center tonearm screw and the other end to the chassis plate of your Reduction makes a difference.

[Karl5150]

Thanks Paul, I tried the wire from the ground post on the Reduction to anything metal (not much, mostly plastic) on the tonearm with no luck. I used the probe from my DMM, and it got even noisier when i touched it to the main bearing bolt on the underside of the TT. I guess the next step will be to remove the cover and see if grounding directly to the motor chassis helps.

[maryc27182]

Did you happen to stumble across this thread while you were trying to figure this out?

https://www.vinylengine.com/turntable_forum/viewtopic.php?t=42514

There's a ground tab that can come loose inside the tonearm. I'm not sure that's your issue but it might be worth checking. Have you tried running an extension cord from another outlet/circuit to make sure it's not a ground loop? Odd that it's only just manifested. Did you change anything in your system?

[Karl5150]

"maryc",
Thanks for the link, I never realized this was such a well documented situation. Looks like a path forward.
Karl

[Deluk]

Note that Rega turntables have a lifetime guarantee. If you are the original owner and you haven't yet attempted to "fix" it I'd say it was best to talk to a dealer. You could email Rega and ask for advice. Copying that link to them as well might add some weight to your request.
See Michael Fremers visit to Rega videos on the tube just a few days ago.
There are 5 interesting parts.

[maryc27182]

I ran across this:

Grounding ... two grounds inside the arm. One is in the arm tube itself. A spring wegde/clip behind the counterweight stub, contacting the stub threads. Once you unscrew the stub you will see it.

  and

There is a second ground of the arm base itself. Rega does that with a small, copper L shaped spring tag. It wedges between the base plug and the inside of the arm base. So both the arm tube itself and the arm base are grounded.

Both from https://www.vinylengine.com/turntable_forum/viewtopic.php?f=32&t=42245&start=30 from user Laudanum, who is on this forum too (Laudanum has actually done this rewiring. I have not.) Most of that thread is about rewiring the tonearm, but if you do have a grounding issue in the arm, it looks like there are two places it is grounded.

These posts say the wires are very fragile. FYI.

Mary

[Karl5150]

Thanks for all the feedback.
My audio rack is in a dedicated space in the living room, so without major upheaval, my outlet options are limited.
First I tried plugging into the only single outlet/breaker combo I have, (one I added in the garage for workbench power) it required a long heavy-duty extension cord and didn't help. In fact it was louder with the TT motor on, the opposite of the situation with the TT plugged directly into the shared "high grade" audio outlet.
Second I tried plugging into an outlet closer by, but on another circuit, requiring a much shorter extension, still no luck.
So...off with the motor cover and back into the system. With one end of a wire connected to the Reduction ground post and the other touching the motor body.....progress.
With the volume set higher than I normally listen the noise was greatly reduced, and once the TT was switched on it dropped into the very low system noise. You have to really listen for it mixed with the ambient noise that slips in through the closed back headphones.
For now I will make the ground "permanent" and see if I can live with the fix.
Thanks again,
Karl