Help Please - Loose Collar on DIN = Hum

e d o posted:

I'm getting a loud hum with the new lead when the DIN collar is slightly loose but not when it's fully tight. Any thoughts?

Keep the DIN collar fully tight as it was designed.

Do you have the same hum if you use a standard Naim lead?

If not, I would actually ask for a replacement as a loud humming noise can be indicative of a poorly soldered connection (most likely earth).

Use a genuine Naim cable

Adam Zielinski posted:

Do you have the same hum if you use a standard Naim lead?

If not, I would actually ask for a replacement as a loud humming noise can be indicative of a poorly soldered connection (most likely earth).

I agree with this

No issues with my other cables. Naim DIN/DIN is fine, as is the other two (older) Chord RCA/DIN cables I have. I don't have a Naim RCA/DIN. The issue happens on other inputs as well. I guess I'll just keep the collar tight on this lead. It's the best sounding of my 3 RCA cables. Maybe there is a dodgy joint in the DIN. I've read many times here that sound is improved with loose collars though.

It suggests to me the the collar is linked to signal return on your questionable lead... this is not how Naim design their leads to work with their systems for max sound quality... signal return is specific to a single pin in the DIN plug.... the collar is used by Naim for chassis grounding. There should onlly be ONE point where ground and signal return is combined on a Naim system... this is either a Naim CD player or a Naim source where the ground switch is slid from float to chassis... 

THerefore your suspect lead might be affecting the SQ of all inputs to a slight degree, unless you know for sure that all other sources are floating and this particular lead is actually providing the ground - signal return connection... I feel unlikely but is possible. 

I really would be inclined not to use that lead on a Naim system... or get it checked by Naim or dealer if you are not sure... the behaviour you describe is not right for Naim systems.

Simon, thanks. I will have it checked.

Tightening the collar should have no effect on the cable.
This sounds like a cable fault at the DIN end, specifically a poor connection, probably at the 0V pin (Pin 2, the middle one). 

My guess is that when you tighten the collar you slightly alter the alignment of the body of the DIN to the pins and one or both of the 0V wires looses contact with the pin.  I've previously known a commercially made lead where tightening the collar caused one of the signal lines to be shorted to the shell causing that channel to cut out.