Humming from my phono

Calling all signal grounding gurus on the forum :grin:

There’s a bit of buzz or hum from my phono when I switch on my turntable. It’s hard to explain but you can almost hear the turntable turning and the noise changes when I switch from 33 to 45rpm.

I have one grounding cable from the tone arm connected to nac252 and the other to my phono stage. The hum goes away when I touch the phono. It is not very noticeable I can only hear it when I crank up my preamp to 12 o’clock but knowing it’s there it’s going to live in my head now :weary: Any suggestions how to get rid of it? There’s unused grounding terminal on my chord s6 block, would connecting this to my phono help?

You have two grounding cables? You should only need one. Either from tonearm to 252 or the phonostage, not both. That will allow a loop. The other option is no ground wire.

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There are actually 4 in my tonearm cable. One from the din plug (connected to NAC), two from left rca and one from another (connected to phono).

Any suggestions?

I have moved the grounding from NAC to phono and it helped a lot but there is still a bit of noise :unamused: is that normal?

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No it should be silent. Any chance of a diagram? I still don’t follow all the earths you mentioned. Generally from the tonearm, there are the left and right RCA or BNC plugs and then a single earth running from the turntable chassis (internally bonded to whatever is needed like arm or motor assembly mount) to the phonostage chassis.

Maybe I am misunderstanding, but what you described seems a lot more complicated. Ultimately you want one path to ground, not several.

Not sure if this helps

If I understand the image correctly, (and I’m not sure I do) your phono leads are the bottom set and each has a ground wire trailing off it. The right ground is terminated to the chassis ground of the phono stage and the left ground trail is unconnected. But you have another ground wire connected to the same chassis ground leading to something out of camera shot. What is that going to?

They’re all from the tonearm.

What is your actual tone arm cable. Could you please name the model.


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This surely is an unusual design. Without the black cable exiting the left channel plug my guess would have been to join the short blue cables at the ground post and to use the long blue one to ground the turntables main bearing.

Please let us know what type of tonearm cable you use, as already suggested by DG

Does the turntable have ot’s own ground terminal screw? And do the tonearm cables also have ground leads trailing off the deck end connected to that or are those ground trails only at the phonostage end? If so, I’d suggest they aren’t turntable ground leads at all but shield grounds.

I would experiment by connecting none of those ground trails to any ground terminal on either end. And run a separate bit of wire between the ground terminal on the deck and the phonostage.

Final sanity check: are those tonearm cables actually proper turntable phonearm interconnects? Or are they regular line level RCA interconnects with grounded shields?

I have only one ground wire going from my TT to my phono preamplifier.

All TT power supplies, phono, and TT and Lingo 4 speed power supplies are fed from a power multi-power point device, which has a common star earth point for three of the 240-volt cables connected to it, eliminating earth loops.

I should also point out that this device is plugged into another power board so all earths have a common reference. The first power board is then plugged into a wall mount power point.

If this sounds confusing, please ask me and I will try to better describe it once I make myself familiar with it again.

The 1 x 3 outlet is the star earth point for three phono power supplies.

The first power board with eight outlets which all my NAIM gear is plugged into has no surge protection.

Mitch in Oz.

According to the third post the cable in question is at least DIN to RCA, otherwise we have to wait for the OP to respond.

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I cannot work out what is going on in the picture, looking at the profile and a bit of googling makes me think that the arm is an Origin Live Enterprise, the cable on their website appears to have plugs matching those in what I think are the input sockets of a Goldnote photo amp. The Origin Live cable appears to me, to have a single flying earth at the arm connector end and one each on the phono amp end.
Then in the OPs picture there are two unconnected earths, one blue, one black.
So, puzzle one, why are they not connected and where might they be connected?
Puzzle two is very much a guess, the blue earth lead on the right channel lead is connected where I might expect, at the earth connector on the phono preamp. The left cable blue earth is not connected. The black one? I really cannot guess. Finally there is a blue lead that goes from the earth terminal across to the right side of the picture. Working back from the Origin Live picture I hazard a guess that it should be connected to the chassis of the turntable.
Only guessing though…

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Do you have your turntable motor or PSU too close to the phono stage?

Phono stages are very sensitive and can pick up noise from the fields put out from motors and PSUs.


Thanks for digging all the information out. The cable shown on the Enterprise product page looks pretty much like the one the OP uses. Oddly enough the product page of the Silver Hybrid 2 external arm cable, which is supposed to be included with the Enterprise, shows a cable with just a single long ground wire attached to the right channel RCA plug.

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I’ve just scared myself, assuming (not always a good thing I know) from the OP’s profile that the arm is mounted on a Goldnote Bellagio Reference, I went to that website and looked at the manual. I would rather build an LP12 from scratch!
That said, there is no clue about earthing the arm. The plinth appears to be acrylic, so that leads me to wonder if the blue wire crossing the picture means the body of the arm is not earthed?

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I would first try with no ground leads connected to anything. It’s not actually strictly mandatory. Rega certainly don’t do grounding on their decks either.

At the moment I have the screen earth and arm earth connected. This combinations seems to produce the least amount of noise / hum.

The cable comes with origin live enterprise tonearm.