Voltage regulation

Posted by: Paul on 31 October 2001

OK OK I know line conditioners are not recommended for NAIM equipment...but can you explain this. I have a Naim 250 - HiCap - 72 all connected to the same power outlet. I also have a 3-way lamp in the room which is connected to a different power outlet (but situated close by). When the lamp is switched on at the lowest output (50 Watt) setting, the Naim 250 makes a big internal humming noise. As soon as I turn the lamp switch to a higher output (100Watt or 150Watt) the amplifier hum dissapears. Can anyone explain why a lower lamp output would increase the "load ?" on the 250 amp and cause a hum when a higher wattage setting eliminates the hum ? Would a line conditioner help the situation ?

Posted on: 31 October 2001 by Mike Sae

I had the exact same situation as you. A table lamp on its "low" setting would make my system hum.

A line condtioner I had left over from an old system did nothing at the lamp end or amp end.

Ditching the lamp was the only option. I can't offer any technical explaination, but my old Rega Mira integrated did this also, so the problem isn't exclusive to Naim amps.

At least you've isolated the culprit. I was baffled until I realized it was the stupid lamp upstairs, on a different circut.

Posted on: 01 November 2001 by Paul

For information, the light uses an incandescant bulb with a three-way switch.