I would like to say hello to everyone. I am new to the forum.
For the past few days, I have been the owner of the NAP250 and NSC222. My problem is a humming (disturbances/interferences) from the speakers, audible from 2-3 meters. The problem appears right after playing music, even for a second. I ruled out power issues and checked various power sources. Moreover, the previous Naim Unity Nova did not have this problem in the same place same power source. The speaker cables were replaced, and the XLR cable as well. When switching the grounding switch on the NSC222, one speaker hums louder than the other alternately. Is there anything else I can do, or is it a device issue? NAP and NSC are brand new.
Thank you all for your help. In my opinion, it might be cold solder joints because when the amplifier warms up, the problem stops, and when it cools down, the buzzing starts again. By the way, the NAP250 gets extremely hot even when it’s not playing. The same happens to me and a friend. It’s so hot that it’s hard to touch. That also doesn’t seem right.
It should not get hot. Are you using incompatible speaker cables? Even then it should not get hot when not playing. Are you saying that your friend has a 250 with the same problem? That sounds very strange. Anyway, speak to your dealer immediately. It’s likely that it/they need to be replaced.
The preliminary diagnosis is this. I’m using a Cardas Clear Cygnus cable, so it’s not cheap, and it turned out that it’s all its fault. The resistance is so high that the amplifier heats up and the speakers buzz. After replacing it, the problem stopped. The worst part is that these cables really sound beautiful!!
It is not the DC Resistance which is the problem, it the Impedance.
“In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit.”
“In electrical circuits, reactance is the opposition presented to alternating current by inductance and capacitance.”
Naim’s own cables - NAC A4 & A5 were designed to provide the correct inductance and capacitance that a Naim power amplifier wants to ‘see’. Linn K20 is a similar cable, which is very inexpensive.
Understanding this can prevent expensive mistakes, with speaker cables…
