recently picked up a arcam phono stage, when connecting to SN2, there is clear buzzing noise. even not turn the arcam on, and the noise is for all SN input channels. if switch back to my old creek phono stage, there is no such problem.
it looks to me to be a typical ground looping noise. have couple questions on it.
can we simply solve it by adding an isolator into signal cable? or alternatively, connect ac ground to arcam chassis. is there any potential safety issue for the second approach?
is this caused by something defective? my SN2 is used about 5years, can some parts go wrong and cause this issue? or the arcam phono is defective?
How is the Arcam powered? Is it isolated? Naim amps like to have a single point to connect signal ground to mains earth. Is another source providing a ground connection?
I assume that this is an Arcam rPhono? Is the TT arm ground connected to the ground on the phono stage? Have you tried linking this to the phono ground terminal on the SN2? Does it make any change to the buzz if you do this? My experience with Naim grounding tends to indicate that a buzz is from a missing ground connection and a hum is from a ground loop i.e. too many connections
I seem to recall someone having a similar issue in the past with an Rphono and Naim amp. I can’t whether or how it was resolved, short of using a ground loop isolator. I’ll see if I can find the old thread when I have a spare moment.
One thing to check is whether it’s picking up hum from proximity to the Supernait’s very large transformer. Have you tried it as far from the SN as you can?
If you get a chance, try removing the ground isolator and adding a wire between mains ground and the ground terminal on the SN2. I think the issue here may be lack of signal ground to mains ground in the system rather than a loop.
confused. we want to avoid a ground loop, sounds like we are connecting signal ground to earth ground. combining with the SN power cable ground, will this make it worse?
don’t know much on electric things, thank you very much.
The SN power cable provides a safety ground. It connects the case of the amplifier to mains earth for safety. It doesn’t connect to the signal ground.
What you are doing by connecting a wire between the SN2 ground terminal and mains earth is providing a connection between signal ground and mains earth. In an all Naim system this would usually happen in the source component, a Naim Network player or CD player.
In your system, this connection is missing. Not usually an issue but sometimes when connecting items with two prong wall wart supplies, leakage current from them can cause an issue.