Hi all.
I have an on-going problem which I have noticed others have experienced as well.
It seems there is a problem marrying a Denon receiver as processor with a Nait5i for amplifying the front speakers – due to an earth hum.
I have isolated the problem down to this: even when the Denon 3802 has no connections whatsoever, and not even plugged to the power line, when the RCA’s onnected to the AV in on the Nait even touches its chassis – it buzzes. I tried to earth it as suggested by some – to a funny effect: when the Denon is muted, it is dead silent; if volume is up, the buzz returns.

It will be a shame replacing a fine receiver for this problem alone.
The Xitel un-earth connector – for some it helped, some reported a nastier hum. It is not an expensive connector.

Jtwurth – you had a similar problem – did you find a solution?

I am really bothered by this...What do I do?


Thank you in advance

Hi nirlevy

I had the same problem with my Nait 5i and Pioneer AX5i. My local Naim dealer suggested I try removing the earth wire from my CD5i three pin power plug. It completely solved the problem without any adverse affects.

Hope this helps.

Don

quote:

I had the same problem with my Nait 5i and Pioneer AX5i. My local Naim dealer suggested I try removing the earth wire from my CD5i three pin power plug. It completely solved the problem without any adverse affects.

Hope this helps.

Don

Hi Don, thank you for your reply.
Do you mean to physically take apart the plug and disconnect the earth wire?
I will try to disconnect the DIN (CD5i to NAIT5i) before.

I think that the proper solution may be more involved.

Must_Be_Earthed.jpg (13 Kb, 54 downloads)

You could try the solution provided here...

First of all, I wanted to thank you all for your replies.
I have tried Don's suggestion - and disconnected the DIN between te CD5 and Nait 5i --) The hum stopped completely!!!

I must admit it puzzles me – as checking the Naim loop never crossed my mind: I kept swapping the other equipment, with no luck so far.
Yet now I am worried by Adam’s caveat – what might be the implications of disconnecting the earth pin from CD5? Nir.

nirlevy

Okay by removing your Din between CD and Nait 5i confirms same problem as I had. Now reconnect your Din. Next remove the earth wire from the CD player's power plug. Hum should be gone.

There is a warning to keep the equipment earthed to minimise the risk of electric shock should a internal electrical short occur. I doubt my Naim dealer would have suggested this remedy if the risk was a concern.

Regards

Don

Does any of you have an idea how can it be that it is the CD5i that introduces the hum to the chain? It really bothers me. Nir

Hi Nirlevy,

The way a Naim earthing system is designed, the metal case of each product that is supplied by mains, is always connected to Mains Earth.
This serves a dual purpose - to enable safe use and to electrically screen operating circuits.
Any piece of Naim equipment, fed by DC supply originating in another, mains supplied piece, gets its vital Signal Earth through its cable connection from the mains supplied piece.

Sometimes, (happens a lot with non-Naim A/V products (like your receiver), which are usually connected to other, different signal sources/converters etc., one of these products, creats in it, a second connection between Mains Earth and Signal Earth.
This second connection, completes a Ground Loop - a well known source of Hum and other forms of audio and video distubances.
The proper way to solve this, would be to find the product that creats the second (or more) connection between Mains and Signal Earths and work from there. Usually devices called "Ground Isolator" or "Ground Block", when connected in series between the "offending" piece and your system, should solve the problem. Those devices are sometimes available as by the company providing your cable/sattelite signal (frequently as a f.o.c. service).

I must emphasize, that not only is it dangerous to your household members to disconnect Any mains supplied product from its Mains Earth, it will also have a detrimental effect on the performance of your audio system.

Ilan