Grounding issue or? - Nova, Roksan Radius, Pre outs AV

I’m struggling to identify and thus rectify a low, almost constant rumbling when playing vinyl.

I’ve not noticed this prior to a recent house move, so I’m speculating as to what has caused this significant deterioration when playing records.

I’ve tried moving my phono stage (Vertete Phono 1) away from the deck itself, but this has made zero difference. I’m wondering whether the arm or tracking has gone awry in the move (nothing visibly has changed and it was securely transferred to the new house).

The only other substantive difference from previous house system is that I have added an AV amp to my set up, the pre outs from the Denon go into one of the Nova’s analogue inputs - but this can’t effect the vinyl playback can it?

Amy thoughts anyone, please?

One way to find out. Unplug the AV amp from the Nova.

Ha! I wonder why I didn’t think of that? Thanks.

What’s the grounding option - floating or default on the rear of the Nova - referring to?

It either connects mains earth to signal ground (default) or floats it. I’d disconnect the AV amp first just to discount that and then go from there.

I’ve unplugged the AV amp from the Nova, but nothing is discernibly different.

With certain records the “low rumbling” for want of a more accurate term is less pronounced which leads me to think it’s a pressing issue, which itself is a variable ever present.

So maybe it’s something that’s been there before and it’s only now in a new room with its own distinctive acoustics that I’m noticing it or maybe that’s not the case and it’s something else I can’t fathom just yet.

Could be - Grounding issues tend to be a low level hum. Just to check, you don’t get any difference when changing position on the Nova grounding switch ?

It’s worth getting your TT checked out if you still get the noise - a constant ‘rumbling’ doesn’t sound right.

Just one more thing, you don’t use Powerline Ethernet adapters do you (Ethernet over the mains) ?

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Is the rumbling only when actually playing records or whenever phono is selected including when the stylus off the disc? If the former I’d suspect some sort of mechanical feedback.

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Yes, the former.

Not had chance to try it yet, but will do in the morning.

No, I don’t use Powerline ethernet adapters.

What does the radius sit on, floor standing rack, wall shelf, sideboard, what?
If you have headphones does it still do it with the speakers off?

The Radius is on its own isolation plinth, which is placed on top of a Kallax unit full of vinyl. A sideboard is arriving this week, so the separates will all be placed on this soon.

I don’t use headphones at all.

Thanks for the input.

Which then leads to the question, what floor construction does the new room have? And in searching for a cure is there a solid, as opposed to plasterboard, wall you can put a shelf on. The deck doesn’t seem to be as isolated as it needs to be at the moment. It’s not out of control feedback but something’s getting through. Turning the sub off might be a good start but is just dodging the issue. Another thing to try is unloading the vinyl from the kallax which might move the resonance up in frequency to where the isolation in the deck can work, or not. I’t very much trial and error.
The headphone test would have given a useful input either way.


That’s all very useful and insightful.

I will investigate and report back accordingly.

I have now switched the grounding option on the back of the Nova - it was set to default but now to floating - and this has removed the low level hum entirely.

Very pleased.

But can someone elucidate: what does “floating” mean and why exactly has it done the job for me, please?

That’s good the hum has gone. Normally in a Naim system, there is one connection point between signal ground and mains earth. Usually in the Naim source component (tuners aside). If you have another item connected that also does this you can get an earth loop and a hum can result. The ground switch on the Nova allows you to lift the signal ground / mains earth connection and break the loop (floating position). I note that your Vertere phono stage has a ground switch with 3 positions (hard, soft, lift) so this may be the other item providing this signal ground / mains earth connection depending on the switch position.

Thanks James, that’s interesting to know.

So, if Naim is set to floating should the Vertere ideally be set to hard, soft or no grounding in this combination?

Hi Charles, Hard or soft (Position 1 or 3). You could also try position 2 (Floating) and put the Nova back to Default.

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Thank you James.

I find it best to set the ground switch position by ear. In many systems it seems to make no difference even when you set the switch to the ‘wrong’ position. In other systems the difference is obvious, as you have discovered.

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I spoke too soon!

I’m now not too sure if the issue is grounding. There is an excessive unpleasant sound, extremely pronounced during quieter sections of music. A noise repetition which corresponds with the rotation of the record, the sound is best described as high level surface noise, but way beyond what I’ve heard before.

Almost sounds like a thump each time the record makes a rotation, the speaker mid range driver visibly moving in synch with the rumbling.

I tried various grounding permutations between the Nova and the Vertere phono stage. I also plugged the Vertere into the wall socket instead of a surge protector, but to no avail.

Any thoughts or suggestions, please?