Signal ground link doubt

Hi everyone

today mounting my new 252 I had a huge doubt when I connected my Rega phono mc. I have seen that both on the phono stage and on the 252 there is a washer for the earth signal (signal ground). is it necessary to connect them with a cable? or with the new turntables you don’t need to do anything and connect only the rca cables from the turntable to the Phono and from the Phono to 252? as always thank you !!


you are correct the earth ground is done through the rca cables

That’s not the complete answer because Naim systems have their signal earth from a Naim CD player, streamer or nDAC. Apart from the CD player (in analog mode) the others must be set to chassis.


I like to know if i have to connect this signal ground

With the signal ground of the 252

Usually not, but using a non-Naim phono stage, you won’t know unless you experience persistent hum, in which case it can give you some options to cure.

Thanks Richard

Just wondering…in my Setup only the Superline is connected to the 552. No CD-Player, streamer, Radio or dac. So Wehre ist signal earth in this case?
Everything sounding pretty fine, by the way…

Well if it ain’t broke then don’t fix it (as the English say)! Yours may be the case where if needed the preamp signal ground is used, but my quick browse of the reference manual made no suggestions. It may depend on local mains wiring regulations. I would think it is worth having a proper signal ground, but @Richard.Dane is better placed to advise particularly as he uses 552 and Superline.


It’s just a ground reference. I’m not an engineer, but I’m aware that Having more than one is usually not a good idea and can cause problems. But If your system sounds good without it is likely just fine as far as I’m aware.

I am an electronics engineer and I agree with Richard.

Richard, In this case there is only a Superline and no other source to provide signal ground.


Sounds good then.

I’m an ex behavioural ecologist and I don’t understand it at all.

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Keep the faith HH. If it’s not humming then it’s good. It’s not that different to ecology.



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Would you operate a 552/500/ND555 with the ND555 set to float? @jodl has 552/500/Superline only.

Having mistakenly run my nDAC on float with CDX2 in digital mode and therefore not earthing the preamp through the non existent DIN, I know that one may not notice. A signal earth presumably ensures a consistent reference provided the mains Earth is really clean/good.


With a 555, 552 and 500 the 555 would be set to chassis. With a 552 500 and Superline the signal earth is via the turntable and the 552 doesn’t have a chassis/floating option. Naim tuners have a floating signal earth so a system with a streamer and a tuner should have the streamer set to chassis.

The 552 has a signal ground which the reference manual didn’t seem to say anything about in my quick peruse. The Superline has a ground for the turntable arm if needed, but it’s not a signal ground. What the manuals do make clear is that the signal ground to the rest of the system is via the preamp. So it remains unclear as the Superline has not got the equivalent of the float/signal ground switch if I recall.

I guess Naim support can answer @jodl, who I’m guessing in German.

Sorry to be posting late, but I have been making sourdough bread for baking in the morning! Bed now.


The ground post on the NAC552 is there if you need it. For example, most likely use is if you are running a Prefix powered from AUX2, then you may find that you need to attach the ground wire to the ground post in order to minimise hum.

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