I have recently upgraded my amplifier from a Yamaha A-S501. I’ve had the Pioneer A-40AE and A-50DA before, and also had a Yamaha A-S1200 for a brief time.
I have always had exactly the same equipment plugged into each amp… Pioneer N-30AE network streamer, and my Pro-Ject Debut Pro turntable connected directly to a Pro-Ject Phono Box S2.
On Thursday I took delivery of a brand new Naim Nait XS 3 amplifier. I didn’t have time to set it up when I got it, but was able to last night.
I have heard great things about the phono stage in the Naim so decided to use that directly to begin with. There is a really deep, bassy, Hum when the phono input is selected on the amp. When selecting other inputs such as Tuner or CD for example the hum is there but is only audible when I turn up the volume. This is happening when everything connected (streamer/turntable) is either ON or OFF regardless.
I don’t know what to do, and wonder if I have a faulty amp out the box?
It’s never happened on any of the other amps I had owned before, and I think at this price point it shouldn’t happen on the Naim at all.
This isn’t a cable, this is the condition you are trying to resolve. A ground loop is typically caused by competing earthing arrangements of 2 or more devices.
There will be a “right” way of connecting all of your hifi, you might need to introduce a dedicated cable to earth the system.
Sorry mate, yes I meant my ground wire goes from TT to ground of the S2 Phono Box. Then using the Chord C-Line RCA cables I have are connected to CD in on the Naim (just using that as Line In input at the moment)
So when both TT/S2 phono box and Pioneer streamer connected to the amp via RCA I get the loud hum. Loud on Phono input as per YouTube clip, but audible (yet quieter) on all other inputs as explained above.
I have disconnected the TT/S2 Phono box, just leaving the streamer plugged in. Still loud hum.
I then decided to unplug everything (streamer included) and when unplugging the last RCA cable the hum stopped.
But as soon as I put just one RCA cable back in to the amp - bang. It’s humming again.
I have just disconnected the whole lot and replaced the amp with my Yamaha A-S501, and connecting everything up exactly the same as Naim and the hum is not there. It’s perfectly quiet.
It has to be something that the Naim doesn’t like. I don’t get it.
Nope. So if I pull any RCA cables out but leave just one in, the hum is still there. If I pull ALL RCA cables out then the hum is gone.
BUT just by putting in one RCA cable back in (doesn’t matter which one) the Hum is back.
I’ve just disconnected the whole lot and replaced with my old Yamaha A-S501. Put in all the same cables and connect exactly how I did with the Naim. The A-S501 is as quiet as a mouse. No Hum. Nothing.
Must be something the Naim doesn’t like in my set up. I don’t get it
Whatever device (streamer?) is connected using the RCA cable is the cause of your earth hum (50hz in the UK or 60hz if you’re in North America) and that device likely needs to be separately earthed to prevent the hum.
The way Naim equipment is earthed differs from most other makers.
It’s likely because the Naim amp is properly earthed through the mains, whereas the other items aren’t so float but once an earth is presented by the Naim amp take the signal ground route to earth via the RCAs, which gives hum. Ways to solve this are to try earthing the pioneer of using a ground loop isolator.
Cheers mate. So regardless of device it’s still doing it. So if only the Pioneer streamer is connected, it hums. If only the Pro-Ject Turntable/S2 box is connected, it hums.
Thanks mate. Just replied to someone else. So really I need to earth both Pioneer streamer, and Pro-Ject TT/S2 box.
I have no idea how to do this lol. Is it easy to do? I really need a cheap solution considering the expense of the amp on the first place. I have no funds left for £100 power supplies haha!
I’ve never had to do it, but it seems relatively straightforward to do. IIRC @james_n has offered a successful solution in the past involving a wire from the chassis of a floating item to the earth of a mains plug. There are also past threads on here that have dealt with similar issues and others have provided various solutions to the issue.
In the first instance, I would run a single wire from the metal outer box (loosen a screw to attach a wire) to a known earthing point such as the screw on a UK mains socket - which should be connected to earth. Or wire the single wire into the earth pin of a UK 3-pin plug.
I have had to do this for a friend on his Naim Nait 5 which hummed when connected to his DVD player.
I ran a single wire from the DVD player’s case to the screw on the side of the socket and it cured his hum.
Alternatively, you can buy a cheap “earth loop” or “Ground Loop” isolator off eBay / amazon.
On Amazon look for “Conext Link RCA Stereo 2 Channel Ground Loop Isolator Signal” which should cost around £8.00 which will be fine to establish if this is the problem you have.