Hum from amp - should I worry?

It is the amp itself for certain - not the speakers. I called Meridian and they said something about the transformer coil causing it, but that it wouldn't effect my performance. The hum has actually died down to almost nothing since I made this post, but then again, I'm still concerned. So far, no effect on performance. We'll see. Thanks for your feedback.

I have a Belles 150 A hot Rod, that has a transformer that hums once in a will. According to David Belles this is caused by to much voltage or to little in the power service to my house. I do not know if this is true, but the amp has been dead quite for weeks.

I have a Meridian 557. IT doesn't hum unless I use XLR interconnects without using the shorter plugs into the RCA inputs. If you put your ear next tothe 557 you will hear a slight hum in the unit. Inaudible from a foot away.

Hey, thanks Tap3 & 7671 - I've been listening closely since my post went up and as you said 7671, the hum is now only audible when my ear is pressed against the face of the amp. When I first heard it, it was audible away from the amp, but it only lasted for a few minutes. Maybe there was a power service problem that morning. Who knows - the amp still plays great, but I just hope it's not a sign of something worse to come. Thanks.

Enjoy the 557. It is a great amp that has been missed by the audio industry!! When coupled to the Meridian 502 pre-amp and 508.24 cd player, it is awesome sounding.